Abnormal preoperative haematological parameters in Endometrial cancer; reflecting tumour aggressiveness or reduced response to radiotherapy?

Abstract

Background

In endometrial cancer (EC), preoperative anaemia, thrombocytosis and leucocytosis appear to be associated with worse prognosis. It remains unclear whether these parameters solely reflect tumour aggressiveness, or also impact response to adjuvant treatment. Therefore, our primary aim is to evaluate the prognostic relevance of anaemia, thrombocytosis and leucocytosis on survival in EC. Secondary, to explore their predictive relevance in response to radiotherapy in EC.

Methods

A retrospective multicentre cohort study was performed within 10 hospitals. Preoperative haematological parameters were defined as: Anaemia – haemoglobin <7.45 mmol/L (<12 g/Dl), thrombocytosis – platelets >400 × 10⁹ platelets/L, leucocytosis – leukocytes >10 × 10⁹/L. The relationship of haematological parameters with clinicopathological characteristics, ESGO/ESTRO/ESP risk groups and survival were evaluated. Furthermore, the predictive value of haematological parameters was determined on the overall response to adjuvant radiotherapy and for the ESGO/ESTRO/ESP intermediate-risk group solely receiving radiotherapy.

Results

A total of 894 patients were included with a median follow-up of 4.5 years. Anaemia was present in 103 (11.5%), thrombocytosis in 79 (8.8%) and leucocytosis in 114 (12.7%) patients. The presence of anaemia or thrombocytosis was significantly associated with ESGO/ESTRO/ESP high-risk (respectively, P = 0.002 and P = 0.041). In the entire cohort, anaemia remained independently associated with decreased disease-specific survival (HR 2.31, 95% CI (1.19–4.50), P = 0.013) after adjusting for age, the abnormal haematological parameters and ESGO/ESTRO/ESP risk groups. In patients that were treated with adjuvant radiotherapy (n = 239), anaemia was associated with significant reduced 5-year disease-specific and recurrence-free survival (P = 0.005 and P = 0.025, respectively). In ESGO/ESTRO/ESP intermediate risk patients that received solely vaginal brachytherapy (n = 74), anaemia was associated with reduced disease-specific survival (P = 0.041).

Conclusions

Current data demonstrate the importance of preoperative anaemia as independent prognostic factor in patients with EC. Moreover, anaemia seems to be associated with reduced response to radiotherapy. Prospective validation in a larger study cohort is needed to verify anaemia as predictive biomarker for radiotherapy.

• What is already known on this subject? In endometrial cancer, preoperative abnormal haematological parameters like, anaemia, thrombocytosis and leucocytosis appears to be associated with FIGO advanced-stage and unfavourable outcome.

• What do the results of this study add? It remains unclear whether anaemia, thrombocytosis or leucocytosis solely reflecting worse prognosis by advanced tumour stage, or also impact response to adjuvant treatment. Current data demonstrate that anaemia is independent associated with decreased disease-specific survival and anaemia seems related with reduced response to radiotherapy and in specific to vaginal brachytherapy in ESGO/ESTRO/ESP intermediate risk patients.

• What are the implications of these findings for clinical practice and/or further research? Specific applied adjuvant treatment is needed if patients with anaemia have a reduced response to radiotherapy in EC. Prospective validation in a larger study cohort is required to verify anaemia as predictive biomarker for radiotherapy and to further evaluate the prognostic/predictive impact of anaemia in addition to the molecular subgroups.

PLAIN LANGUAGE SUMMARY

In this study we focused on three specific blood values before surgery to predict survival outcomes in endometrial cancer patients: low haemoglobin (anaemia), high platelet count (thrombocytosis) and high white blood cell count (leucocytosis). We studied 894 patients with endometrial cancer over about 4.5 years, in which 11.5% had anaemia, 8.8% thrombocytosis and 12.7% leucocytosis. Anaemia was linked to a lower chance of surviving endometrial cancer, even after we considering patients' age, thrombocytosis, leucocytosis and the endometrial cancer risk classification groups. In patients who received radiotherapy after surgery (293 patients), anaemia was linked to a lower change of surviving and cancer coming back within 5 years. In patients within the intermediate endometrial cancer risk classification group who only received specific radiotherapy (74 patients), anaemia was even linked with lower chance of survival. In conclusion, anaemia is an important factor in predicting endometrial cancer outcomes, and it might also make radiotherapy less effective for some patients.

Keywords:

• Anaemia
• radiotherapy
• vaginal brachytherapy

Introduction

Endometrial cancer (EC) is the most common gynaecologic malignancy in industrialised countries with incidence rates rising due to ageing and obesity. Most patients are diagnosed with low-grade EC (grade 1–2 endometrioid EC), and generally have a favourable prognosis (Bokhman, 1983). Around 20% of patients are diagnosed with high-grade EC (grade 3 endometrioid EC and non-endometrioid EC), have an overall poor prognosis and are associated with an increased risk of regional or distant metastases (Bokhman 1983). Currently, primary surgical treatment is based on preoperative tumour grade and histology. Yet, in some patients fertility preservation could be considered based on: (I) grade 1 tumour histology, (II) tumour restricted to the endometrium by imaging, (III) no contra-indications of hormonal treatment, (IV) counselling about not the standard care of EC, including the risks. Patients with high-grade EC or with deep myometrial invasion are not recommended for fertility preservation treatment due to high risk of nodal metastasis (Mutlu et al. 2022, Zaami et al. 2022). Immunohistochemical or molecular markers could be additional helpful facilitate decision making for fertility-sparing treatment (Giampaolino et al. 2022, Mutlu et al. 2022, Tanos et al. 2022, Zaami et al. 2022, Gullo et al. 2023).

According to the recent ESGO/ESTRO/ESP (European Society of Gynaecological Oncology – European SocieTy for Radiotherapy and Oncology – European Society of Pathology) guideline, adjuvant treatment is based on risk classification groups incorporating FIGO (Federation International of Gynaecology and Obstetrics) stage, tumour grade and histology, lymphovascular space invasion (LVSI) and with or without molecular markers.(Concin et al. 2021) Often routinely obtained preoperative clinical biomarkers, such as haematological parameters, may contribute to identification of patients with extended disease and/or aggressive tumour behaviour that might respond differently to adjuvant therapy (Koukourakis et al. 2000, Cho et al. 2016, Reijnen et al. 2020).

Endometrial carcinogenesis is characterised by chronic inflammation with elevated pro-inflammatory cytokines and acute phase proteins (Modugno et al. 2005). Overexpression of inflammatory cytokines could contribute to the development of cancer-related anaemia, thrombocytosis and leucocytosis, and could generate a pro-tumorigenic environment (Birgegård et al. 2005, Worley et al. 2012, Nie et al. 2019, Ye et al. 2020). Preoperative abnormal haematological parameters like anaemia, thrombocytosis and/or leucocytosis, have been shown to be associated with FIGO advanced-stage and unfavourable outcome, however, results remain conflicting (Tamussino et al. 2001, Njølstad et al. 2013, Bai et al. 2019, Nie et al. 2019, Salem et al. 2020, Ye et al. 2020, Abu-Zaid et al. 2021a, Abu-Zaid et al. 2021b).

Several studies showed an adverse impact of anaemia to radiotherapy (RT) response in solid tumours, explained by the fact that anaemia is proposed to be a surrogate maker for tumour hypoxia (Koukourakis et al. 2000, Nordsmark and Overgaard 2004). Hypoxia is very common in solid tumours and leads to cellular stress response, which allows tumour cells to survive. In addition, these hypoxic conditions may also protect tumour cells from downstream DNA breaks and lethality induced by radiotherapy (Durand 1991, Moon et al. 2022). Within gynaecological tumours, leucocytosis was also observed to have an adverse predictive impact on RT response (Cho et al. 2016). So far, no studies reported the impact of thrombocytosis on RT in solid tumours.

Based on conflicting results in outcome of abnormal preoperative haematological parameters in EC, we aim to evaluate the prognostic relevance of anaemia, thrombocytosis and leucocytosis on survival. Second, we aim to explore the predictive relevance of these abnormal haematological parameters on response to adjuvant RT. We hypothesise that patients with anaemia, thrombocytosis and/or leucocytosis have reduced survival due to advanced-stage EC, and anaemia might have negative impact on response to adjuvant RT.

Material and methods

Study cohort

A multicentre cohort study was performed with a combination of prospective and retrospectively collected data in patients diagnosed with EC. This study is a collaboration between the Netherlands and the United Kingdom (UK) by which data of nine hospitals in the Netherlands (PIpelle Prospective ENDOmetrial carcinoma (PIPENDO) cohort (Visser et al. 2015)) and one in the UK (Bouwman et al. 2015) were merged. The design and patient cohort of both cohorts, including 946 patients in total (PIPENDO and UK), have been published previously (Bouwman et al. 2015, Visser et al. 2015). A study flowchart is shown in Figure 1. This study followed the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.

Figure 1. Study flowchart.

Data collection

All patients were surgically treated between 2006 and 2015. For the Dutch participating hospitals patient characteristics, postoperative tumour histology, grade and FIGO staging were collected prospectively (Visser et al. 2015). Preoperative haemoglobin level, platelet- and leukocyte counts were collected retrospectively from hospital records. For the UK centre, all clinicopathological characteristics and preoperative haematological parameters were collected retrospectively (Bouwman et al. 2015). Regarding to the data collection of nodal status, in the Netherlands and UK surgical staging is selectively performed in patients with preoperative high-grade histology (grade 3 endometrioid EC and non-endometrioid EC) and in case of clinical suspicion of extended disease, according to the Dutch and British EC guideline (Sundar et al. 2017, Gynaecologie 2018).

The sole additional inclusion criteria used for this study was that patients were only included if at least one of the three preoperative haematological parameters was conducted ≤ 6 weeks prior to surgery, resulting in 896 patients.

Statistical analysis

The haematological parameters were analysed as a dichotomous value, with defined cut-offs. Anaemia was defined according to the World Health Organisation as haemoglobin level <7.45 mmol/L (<12 g/Dl) (McLean et al. 2009), thrombocytosis as platelet counts >400 × 10^9/L according to multiple studies involving gynaecologic malignancies (Nie et al. 2019), and leucocytosis as leukocyte counts >10 × 10⁹/L (Worley et al. 2012).

The risk classification groups were classified according to the ESGO/ESTRO/ESP guideline; low, intermediate, high-intermediate, high and advanced/metastatic risk group (Concin et al. 2021). To explore the response on RT, all patients who received solely adjuvant RT were included for the second analysis. To further refine response of RT and in order to prevent treatment bias by including patients who were not treated according to the recent guideline, patients classified as ESGO/ESTRO/ESP intermediate risk were only included (flowchart secondary analysis, Figure S1). According to the guideline, these patients are recommended to receive adjuvant vaginal brachytherapy (VBT) (Concin et al. 2021), whereas other risk classification groups include observation or combined chemoradiotherapy.

For statistical analyses, Statistical Package for the Social Sciences, version 25.0 (IBM, New York, NY, USA) was applied. The results were considered significant with P-value less than 0.05 (P < 0.05). Clinicopathological characteristics between dichotomous haematological subgroups were compared using the χ² or Fisher’s exact test for categorical data, and the non-parametric Mann-Whitney U-test for continuous variables. Association between exposure and outcome are shown as odds ratio (OR), 95% Confidence Interval (CI) and P-value. Survival analyses were performed using Kaplan-Meier curves and univariable and multivariable Cox-regression. Associations are shown as hazard ratio (HR), 95% CI and P-value. Disease-specific survival (DSS) was defined as time from date of diagnosis to date of death by EC and recurrence-free survival (RFS) was defined as time from surgery to time of recurrence from EC disease, all censored by date of last contact. Within the survival analysis, patients with abnormal haematological parameters and an increased or reduced/decreased DSS or RFS were compared to the reference group, patients with normal haematological parameters.

Ethical approval

For the participating Dutch centres, this study was revised and approved by the local medical ethical committee Brabant on November 2018 (Protocol 1129, METC, Brabant). For the participating UK centre, ethical approval was obtained through the London–Fulham Ethical committee on January 2015 (reference number 15/LO/0149) and the study had full hospital approval.

Results

Patients

A total of 896 EC patients were included with a least one haematological parameter. Two patients had abnormally high leukocyte count (>50 × 10⁹/L) due to chronic lymphatic leukaemia and unknown cause, these patients were excluded, resulting in 894 EC patients (54.8% British and 45.2% Dutch) included in this study with a median follow-up of 4.5 years (range 0–10 years) (Figure 1). Clinicopathological characteristics of the study cohort are shown in Table 1. Median age was 65.9 (27.2–93.8) years and median body mass index 29.7 (16.4–60.9) kg/m². Of 653 (73.0%) EC patients all three haematological parameters were available. Median preoperative haemoglobin level was 8.4 mmol/L, median platelet count 298.3 × 10⁹ platelets/L and median leukocyte count 8.1 × 10⁹/L. Anaemia was present in 103 (11.3%), thrombocytosis in 79 (8.6%) and leucocytosis in 114 patients (12.5%). Most patients were diagnosed with low-grade (grade 1–2), FIGO stage I–II and endometrioid EC (respectively, 69.4, 90.2 and 82.2%). Lymphadenectomy was performed in 205 patients (22.9%) of whom 34 (16.5%) had lymph node metastasis. Adjuvant treatment was administered in 344 patients (38.5%). A total of 239 patients (69.5%) received RT of which 132 patients (55.2%) VBT and 107 patients (44.8%) external beam radiation therapy with or without VBT. Hundred and twenty-four patients (13.9%) developed recurrent EC, and 160 patients (17.9%) were deceased of which 99 (61.8%) deaths were directly related to EC.

Table 1. Baseline clinicopathological characteristics.

Patient characteristics		Total (n = 894)
Age (years)		65.9 (27.2–93.8)
BMI (kg/m^2)		29.7 (16.4–60.9)
Serum values
Haemoglobin mmol/L		8.4 (3.9–10.6)
Haemoglobin <7.45 mmol/L		103 (11.3)
Platelets ×10^9 /L		298.3 (13.9–781.0)
Platelets >400×10^9		79 (8.6)
Leukocytes ×10^9/L		8.1 (2.2–33.5)
Leukocytes >10×10^9/L		114 (12.5)
Final tumour histology
Tumour Grade	1–2	620 (69.4)
	3	274 (30.6)
Histology	Endometrioid	735 (82.2)
	Non-endometrioid	159 (17.8)
LVSI	Yes	177 (19.8)
	No	717 (80.2)
FIGO stage	Early (I–II)	806 (90.2)
	Advanced (III–IV)	88 (9.8)
Lymph node status	Positive (N1)	34 (3.8)
	Negative (N0)	171 (19.1)
	Unknown† (Nx)	689 (77.1)
ESGO/ESTRO/ESP risk groups	Low	409 (45.7)
	Intermediate	159 (17.8)
	High-intermediate	162 (18.1)
	High	140 (15.7)
	Advanced/metastatic	24 (2.7)
Adjuvant treatment
None		550 (61.5)
RT	VBT	132 (14.8)
	EBRT (+/− VBT)	107 (11.9)
CT + CRT		100 (11.2)
Other		5 (0.6)
Outcome
Recurrence	Yes	124 (13.9)
	No	770 (86.1)
Mortality	Overall	160 (17.9)
	EC-related	99 (11.1)

Data is presented in numbers (%) or median (IQR).

Abbreviations: Number (n), Federation International Gynaecology Obstetric (FIGO), European Society of Gynaecological Oncology (ESGO), European SocieTy for Radiotherapy and Oncology (ESTRO), European Society of Pathology (ESP), Radiotherapy (RT), Vaginal brachytherapy (VBT), External beam radiation therapy (EBRT), Chemotherapy (CT), Chemoradiation (CRT), Endometrial cancer (EC).

^† No lymphadenectomy performed.

Preoperative haemoglobin-, platelet- and leukocyte level in relation to clinicopathological characteristics are shown in Table 2. Haemoglobin level was measured in 894 (100.0%), platelet count in 721 (80.6%) and leukocyte count in 667 patients (74.6%). Patients with anaemia were significantly associated with grade 3 EC (OR 1.81, 95% CI 1.18–2.79), LVSI (OR 1.61, 95% CI 1.00–2.57), and ESGO/ESTRO/ESP high risk (OR 2.11, 95% CI 1.30–3.42). The presence of thrombocytosis was significantly associated with LVSI (OR 1.77, 95% CI 1.04–2.99), and ESGO/ESTRO/ESP high risk (OR 1.78, 95% CI 1.02–3.11). Leucocytosis was significantly associated with ESGO/ESTRO/ESP advanced/metastatic risk (OR 2.72, 95% CI 1.06–6.97).

Table 2. Clinicopathological characteristics in relation to haemoglobin-, leukocytes- and thrombocytosis-level.

		Normal haemoglobin (n = 791)	Anaemia (n = 103)	P	Normal platelets (n = 642)	Thrombocytosis (n = 79)	P	Normal leukocytes (n = 553)	Leucocytosis (n = 114)	P
Patient characteristics
Age		65.7 (27.2–91.0)	68.2 (33.8–93.8)	0.246	66.0 (31.2–93.8)	64.0 (27.2–90.7)	0.017*	66.0 (31.2–93.8)	65.0 (27.2–86.0)	0.386
Final tumour histology
Tumour grade	1–2	560 (70.8)	60 (58.3)	0.009*	448 (69.8)	52 (65.8)	0.471	383 (69.3)	81 (71.1)	0.705
	3	231 (29.2)	43 (41.7)		194 (30.2)	27 (34.2)		170 (30.7)	33 (28.9)
Endometrioid		656 (82.9)	79 (76.7)	0.120	531 (82.7)	62 (78.5)	0.353	455 (81.7)	94 (82.5)	0.856
Non-endometrioid		135 (17.1)	24 (23.3)		111 (17.3)	17 (21.5)		101 (18.3)	20 (17.5)
LVSI	Yes	149 (18.8)	28 (27.2)	0.046*	121 (18.8)	23 (29.1)	0.031*	109 (19.7)	26 (22.8)	0.454
	No	642 (81.2)	75 (72.8)		521 (81.2)	56 (70.9)		444 (80.3)	88 (77.2)
ESGO/ESTRO/ESP risk groups
Low risk		372 (47.0)	37 (35.9)	0.033*	309 (48.1)	31 (39.2)	0.135	270 (48.8)	53 (46.5)	0.650
Intermediate risk		146 (18.5)	12 (11.7)	0.088	105 (16.4)	7 (8.9)	0.083	77 (13.9)	17 (14.9)	0.782
High-intermediate risk		140 (17.7)	22 (21.4)	0.364	114 (17.8)	17 (21.5)	0.413	101 (18.3)	17 (14.9)	0.393
High risk		114 (14.4)	27 (26.2)	0.002*	97 (15.1)	19 (24.1)	0.041*	92 (16.6)	20 (17.5)	0.813
Advanced/metastatic		19 (2.4)	5 (4.9)	0.148	17 (2.6)	5 (6.3)	0.073	13 (2.4)	7 (6.2)	0.031*
Adjuvant treatment
None		499 (63.1)	51 (49.5)	0.009*	412 (64.2)	42 (53.2)	0.066	361 (65.2)	64 (56.1)	0.069
RT	VBT	122 (15.4)	10 (9.7)	0.124	87 (13.6)	3 (3.8)	0.013*	58 (10.5)	15 (13.2)	0.406
	EBRT (+/− VBT)	87 (11.0)	20 (19.4)	0.012*	75 (11.6)	14 (17.7)	0.124	69 (12.5)	17 (14.9)	0.480
CT + CRT		79 (10.0)	21 (20.4)	0.002*	65 (10.1)	19 (24.0)	<0.001*	62 (11.3)	17 (15.0)	0.260
Other		4 (0.5)	1 (1.0)	0.459	3 (0.5)	1 (1.3)	0.372	3 (0.5)	1 (0.8)	0.528

Data is presented in numbers (%), median (range).

Abbreviations: number (n), Lymphovascular space invasion (LVSI), European Society of Gynaecological Oncology (ESGO), European SocieTy for Radiotherapy and Oncology (ESTRO), European Society of Pathology (ESP), Radiotherapy (RT), Vaginal brachytherapy (VBT), External beam radiation therapy (EBRT), Chemotherapy (CT), Chemoradiation (CRT).

* P < 0.05.

Prognostic outcome

The 5-year DSS and RFS of preoperative anaemia, thrombocytosis and leucocytosis are shown in Figure 2A–F. Patients with anaemia had a significant reduced 5-year DSS and RFS compared to patients with normal haemoglobin level (respectively, P < 0.001 and P < 0.001) (Figure 2A, D). Patients with thrombocytosis showed significant reduced 5-year DSS compared to normal platelet count (P = 0.023), no difference was found for RFS (Figure 2B, E). For patients with leucocytosis compared with normal leukocyte count, no significant difference in DSS and RFS was found (Figure 2C, F).

Figure 2. (A–F) 5-year disease-specific survival (DSS) and recurrence-free survival (RFS) of patients with normal and abnormal haematological parameters. (A) 5-year DSS of patients with and without anaemia. (B) 5-year DSS of patients with and without thrombocytosis. (C) 5-year DSS of patients with and without leucocytosis. (D) 5-year RFS of patients with and without anaemia. (E) 5-year RFS of patients with and without thrombocytosis. (F) 5-year RFS of patients with and without leucocytosis.

In multivariable analysis after adjusting for age, the three abnormal haematological parameters and the ESGO/ESTRO/ESP risk groups, only anaemia, age and ESGO/ESTRO/ESP high- and advanced/metastatic risk groups remained independently associated with a reduced DSS. None of the haematological parameters were independently associated with a decreased RFS (Table 3).

Table 3. Cox regression univariable and multivariable analysis of disease-specific survival (DSS) and recurrence-free survival (RFS).

Variable	Univariable DSS		Multivariable DSS Event 66		Univariable RFS		Multivariable RFS Event 78
	HR (95% CI)	P value	HR (95% CI)	P value	HR (95% CI)	P value	HR (95% CI)	P value
Patient characteristics
Age (continuous)	1.04 (1.02–1.06)	<0.001*	1.03 (1.00–1.06)	0.009*	1.04 (1.01–1.05)	<0.001*	1.03 (1.00–1.05)	0.022*
Haematological parameters
Anaemia	3.19 (2.02–5.02)	<0.001*	2.31 (1.19–4.50)	0.013*	2.32 (1.49–3.60)	<0.001*	1.71 (0.91–3.19)	0.091
Thrombocytosis	1.90 (1.08–3.34)	0.025*	1.06 (0.49–2.30)	0.872	1.31 (0.73–2.36)	0.363	0.70 (0.32–1.55)	0.382
Leucocytosis	1.65 (0.95–2.86)	0.074	1.37 (0.74–2.55)	0.312	1.45 (0.85–2.44)	0.168	1.53 (0.84–2.74)	0.159
ESGO/ESTRO/ESP risk groups
Low	1		1		1		1
Intermediate	7.59 (3.01–19.12)	<0.001*	3.06 (0.98–9.53)	0.053	6.20 (3.06–12.55)	<0.001*	2.38 (0.88–6.39)	0.087
High-intermediate	3.90 (1.38–10.96)	0.010*	1.59 (0.44–5.65)	0.472	5.23 (2.56–10.89)	<0.001*	3.43 (1.44–8.16)	0.005*
High	32.66 (13.99–76.23)	<0.001*	18.3 (7.64–43.94)	<0.001*	22.21 (11.64–42.37)	<0.001*	16.78 (8.05–34.83)	<0.001*
Advanced/metastatic	101.97 (40.33–257.79)	<0.001*	72.1 (27.36–189.97)	<0.001*	36.59 (15.79–84.74)	<0.001*	33.68 (13.15–86.29)	<0.001*

Abbreviations: Disease-specific survival (DSS), Recurrence-free survival (RFS), Hazard ratio (HR), Confidence interval (CI), European Society of Gynaecological Oncology (ESGO), European SocieTy for Radiotherapy and Oncology (ESTRO), European Society of Pathology (ESP),.

* P < 0.05.

Predictive outcome

The 5-year DSS and RFS of the preoperative haematological parameters in all patients who received solely adjuvant RT are shown in Figure 3A–F. Anaemia was associated with a significant decreased DSS and RFS compared to normal haemoglobin level (respectively, P = 0.005 and P = 0.025) (Figure 3A, D). Thrombocytosis and leucocytosis did not significantly impact the response to RT (Figure 3B, C, E, F). The 5-year DSS and RFS of the haematological parameters within patients classified as ESGO/ESTRO/ESP intermediate risk who received solely VBT are shown in Figure S2A–E. Patients with anaemia had a significant decreased DSS compared to normal haemoglobin level (P = 0.041), this was not significant for the RFS (P = 0.214). No significant difference in DSS and RFS were found for patients with thrombocytosis or leucocytosis, however numbers were low.

Figure 3. (A–F) 5-year disease-specific survival (DSS) and recurrence-free survival (RFS) of patients with normal and abnormal haematological parameters within patients with solely adjuvant radiotherapy (RT). (A) 5-year DSS of patients with and without anaemia in patient with adjuvant RT. (B) 5-year DSS of patients with and without thrombocytosis in patients with adjuvant RT. (C) 5-year DSS of patients with and without leucocytosis in patients with adjuvant RT. (D) 5-year RFS of patients with and without anaemia with adjuvant RT. (E) 5-year RFS of patients with and without thrombocytosis with adjuvant RT. (F) 5-year RFS of patients with and without leucocytosis with adjuvant RT.

Discussion

In this study, the prognostic and predictive relevance of preoperative abnormal haematological parameters in patients with EC was evaluated. Anaemia was identified as an independent prognostic factor for DSS, along with age and ESGO/ESTRO/ESP ‘high- and advanced/metastatic’ risk. Furthermore, anaemia seemed an overall predictive factor for response to adjuvant RT, and specifically for patients with ESGO/ESTRO/ESP intermediate risk who received solely VBT.

Although most patients with EC present with postmenopausal bleeding as an early symptom, this rarely causes anaemia at diagnosis. Hence, the development of cancer-related anaemia in EC is more likely caused by inflammatory cytokines which results in a shortened survival of red blood cells, suppression of erythroid progenitor cells, impaired iron utilisation, and inadequate erythropoietin (EPO) production (Moliterno and Spivak 1996, Birgegård et al. 2005). Anaemia in patients with an absolute or relative EPO deficiency seems to be more aggressive in solid tumours (Obermair et al. 1998). Therefore, it is suggested that preoperative anaemia in EC could be a biomarker of tumour burden and/or aggressive tumour behaviour (Moliterno and Spivak 1996, Obermair et al. 1998). In our study cohort we observed that patients with anaemia were significantly more often allocated to ESGO/ESTRO/ESP high risk group, grade 3 EC, and the presence of LVSI. In both univariable and multivariable DSS analysis, we found anaemia as independent prognostic factor. To our knowledge, the presence of anaemia has so far not been related to the ESGO/ESTRO/ESP risk groups. Previous studies did show a significantly higher prevalence of anaemia in patients classified into the ESGO/ESTRO/ESP high risk group; FIGO advanced-stage, grade 3 EC and LVSI (Abu-Zaid et al. 2021a). The 5-year RFS was significantly reduced in patients with anaemia compared to those without anaemia. However, anaemia was not an independent prognostic factor for the RFS, comparable to the findings of Wilairat and Benjapibal (2012).

Cancer-related anaemia may also cause tumour hypoxia, which may lead to a reduced response to RT (Durand 1991, Koukourakis et al. 2000, Nordsmark and Overgaard 2004, Moon et al. 2022). Normally, hypoxia will lead to an EPO increase, however, due to the cancer-associated inflammation the EPO production is insufficient and the iron metabolism is impaired. VBT is given for local control of the tumour and EBRT could be applied to control locoregional recurrence (Moon et al. 2022). In patients within our study who received RT and even with solely VBT within the ESGO/ESTRO/ESP intermediate risk group, anaemia was correlated with a significantly reduced DSS. However, numbers were low and therefore multivariable analysis was not achievable. So far, no other studies including EC patients have been performed to compare our findings.

Three recent meta-analyses published the clinicopathological and/or prognostic significance of preoperative thrombocytosis in EC (Bai et al. 2019, Nie et al. 2019, Ye et al. 2020). In line with our findings, a significant association of thrombocytosis with FIGO advanced-stage, LVSI and grade 2–3 EC was found (Bai et al. 2019, Nie et al. 2019) The prognostic relevance, however, still remains conflicting in EC studies, probably due to different used cut-off values for thrombocytosis (Bai et al. 2019, Nie et al. 2019, Ye et al. 2020). Comparable to our study, Njølstad et al. (2013) found a significant reduced DSS of patients with thrombocytosis (Njølstad et al. 2013). However, thrombocytosis as dichotomous value instead of continuous platelet count was not found as independent factor for DSS and RFS (Nie et al. 2019). The pathophysiological mechanism between tumour behaviour and preoperative thrombocytosis is not fully elucidated (Bai et al. 2019). The overexpression of inflammatory cytokines results in an increase of megakaryocyte maturation which causes increased platelet production (Berridge et al. 1988). Some hypothesise that platelets infiltrate tumour tissue and contribute to tumour growth by secreting pro-angiogenic factors and pro-tumorigenic factors, while others suggest a platelet-cancer interaction facilitating cancer cell migration, which contributes cancer metastasis (Li 2016).

The impact of leucocytosis on tumour behaviour may also be explained by upregulation of inflammatory cytokines and haematopoietic growth factor through tumour cells, thus promoting enhanced inflammation, leucocytosis, angiogenesis and tumour cell proliferation (Mantovani et al. 2008, Modugno et al. 2005). We observed a significant association between leucocytosis and the ESGO/ESTRO/ESP advanced/metastatic risk group in our study cohort, however leucocytosis was not significant in univariable and multivariable analysis. A recent meta-analysis found a correlation between leucocytosis and FIGO advanced-stage (Abu-Zaid et al. 2021b), of whom only one study performed a multivariable analysis for RFS with comparable results as our study (Salem et al. 2020).

Due to the pro-angiogenic factors induced with elevated platelet and leukocyte count, its suspected that angiogenesis will lead to a better drug or oxygen access to tumour cells, however, there is a lack of homogeneity of vasculature density in different parts of the same tumour which could affect outcome and response to adjuvant treatment (Koukourakis et al. 2000). Although we did not observe impact of thrombocytosis and/or leucocytosis on response to RT, included numbers were low. In patients with cervical cancer leucocytosis was related to poor response to RT, but due to differences in carcinogenesis it may be difficult to compare those results with EC (Cho et al. 2016).

As shown in this study, some patients are diagnosed with EC during their reproductive years. So far, haematological parameters in solely young women with EC has not been studied. It might be relevant in future studies to evaluate whether these haematological biomarkers could additionally assist in fertility-sparing strategies (including hormonal, surgical and assisted reproductive technologies) in young women with EC.

For hormonal treatment, progestin is recommended as first-line therapy based on the antiproliferative effect of the endometrium. Using hormones in stage IA EEC until completion of childbearing has not been associated with decreased oncologic outcomes compare to women who underwent hysterectomy (97.5% 5-year overall survival) (Giampaolino et al. 2022, Mutlu et al. 2022). Molecular or immunohistochemical markers could help predicting response to hormonal treatment (Giampaolino et al. 2022, Gullo et al. 2023). Conservative surgical treatment consists of hysteroscopic resection followed by oral or intra-uterine devise of progestin. Those women achieved the highest complete remission rate compared with other fertility-sparing strategies (Mutlu et al. 2022). Ovarian preservation needs to be considered in the fertility preserving approach, including other assisted reproductive technologies, that is, oocyte/embryo cryopreservation or ovarian tissue cryopreservation. In which closed vitrification systems are, based on the current available evidence, the safest option for cryopreserved cells (Gullo et al. 2022, Mutlu et al. 2022). There are some limitations inherent to the retrospective design. First, adjuvant treatment was not uniformly applied which could lead to differences in outcome. Second, due to the fact that most of our labs do not run routine complete blood count, platelet- and leukocyte count were not available for all included patients. Finally, complete molecular data according The Cancer Genome Atlas is not available for the patients in this cohort. However, within a subset of the PIPENDO cohort, we do have immunohistochemistry of p53 and mismatch repair proteins. Within patients with p53-abnormal, anaemia was associated with significant reduced DSS and RFS compared to patients with normal haemoglobin (data not shown).

To our knowledge, this is the first study that addressed the relationship of all three, often routinely obtained, preoperative abnormal haematological parameters with clinicopathological characteristics and univariable and multivariable outcome in EC. Other strengths of this study includes its multicentre design resulting in the largest patient cohort to date, and a well-documented and long follow-up period.

Future studies in a prospective study design, may determine the prognostic and/or predictive value of preoperative abnormal haematological markers (more specific anaemia) in addition to the molecular markers in EC. When confirmed, studies should explore in more detail the cause between for example anaemia and impaired prognosis. Furthermore, the value of haematological parameters in young women who are eligible for fertility-sparing strategies needs to be further elucidated.

Conclusion

Our data demonstrated the independent prognostic impact of preoperative anaemia in patients with EC. In addition, anaemia seems to be associated as predictive biomarker for response to radiotherapy. It remains unclear whether preoperative anaemia reflects tumour aggressiveness or reduced response to radiotherapy. So, prospective validation in a larger study cohort is needed to verify anaemia as predictive biomarker for radiotherapy.

Authors’ contribution

SV: Conceptualisation, Data curation, Formal analysis, Investigation, Methodology, Visualisation, Writing – original draft. HD, CR: Conceptualisation, Data curation, Writing – review & editing. AS, NV: Data curation, Writing – review & editing. PG, HN, DvH, BP, MCV: Resources, Writing – review & editing. MS: Conceptualisation, Supervision, Writing – review & editing, Resources. RK: Conceptualisation, Supervision, Writing –review & editing. RB: Resources, Supervision, Writing – review & editing. KG, JP: Conceptualisation, Project administration, Resources, Supervision, Writing –review & editing.

Disclosure statement

The authors report there are no competing interest to declare.

Data availability statement

The data that support the findings of this study are available from the corresponding author, SW, upon reasonable request.

Additional information

Funding

This work was not funded.