Multidisciplinary team conferences promote treatment according to guidelines in rectal cancer

Abstract

Background. Multidisciplinary team (MDT) conferences have been introduced into standard cancer care, though evidence that it benefits the patient is weak. We used the national Swedish Rectal Cancer Register to evaluate predictors for case discussion at a MDT conference and its impact on treatment.

Material and methods. Of the 6760 patients diagnosed with rectal cancer in Sweden between 2007 and 2010, 78% were evaluated at a MDT. Factors that influenced whether a patient was discussed at a preoperative MDT conference were evaluated in 4883 patients, and the impact of MDT evaluation on the implementation of preoperative radiotherapy was evaluated in 1043 patients with pT3c-pT4 M0 tumours, and in 1991 patients with pN+ M0 tumours.

Results. Hospital volume, i.e. the number of rectal cancer surgical procedures performed per year, was the major predictor for MDT evaluation. Patients treated at hospitals with < 29 procedures per year had an odds ratio (OR) for MDT evaluation of 0.15. Age and tumour stage also influenced the chance of MDT evaluation. MDT evaluation significantly predicted the likelihood of being treated with preoperative radiotherapy in patients with pT3c-pT4 M0 tumours (OR 5.06, 95% CI 3.08–8.34), and pN+ M0 (OR 3.55, 95% CI 2.60–4.85), even when corrected for co-morbidity and age.

Conclusion. Patients with rectal cancer treated at high-volume hospitals are more likely to be discussed at a MDT conference, and that is an independent predictor of the use of adjuvant radiotherapy. These results indirectly support the introduction into clinical practice of discussing all rectal cancer patients at MDT conferences, not least those being treated at low-volume hospitals.

Multidisciplinary team (MDT) conferences have been introduced into routine cancer care, although evidence that this benefits treatment selection and outcome is weak [1–3]. Current data, however, suggest that MDT conference recommendations are generally implemented in clinical decision-making and thereby influence treatment [4–7]. A benefit from MDT evaluation as regards prognosis has been reported in gynaecological cancer, head and neck cancer and lung cancer [8–11]. Moreover, MDT evaluation increases patient inclusion into clinical studies [12]. Although the inclusion of MDT conferences in routine patient management clearly has a number of advantages, it is demanding on resources. It is essential, therefore, that scientific evaluation of the impact of MDT evaluation on treatment-related decisions and outcome be performed [2].

Rectal cancer represents an area where the introduction of MDT conferences into clinical management has occurred parallel with refined surgical techniques and altered principles for oncological treatment [2]. The outcome of rectal cancer management has significantly improved with increased overall survival, disease-free survival and a reduction in local recurrence rates [13–15]. Surgery performed by a skilled rectal cancer surgeon, refined imaging, and careful histopathologic evaluation are key factors that have improved outcome in rectal cancer. The role of MDT conferences in the treatment of rectal cancer has been addressed in a few studies only, and from various perspectives. Preoperative MDT conferences with access to magnetic resonance imaging (MRI) results have been shown to reduce the risk of a positive circumferential resection margin [16]. Patients discussed at a MDT conference are also more likely to receive neo-adjuvant therapy for locally advanced rectal cancers and to be considered for surgery for liver metastases [17,18].

System-related as well as patient-related factors have been suggested to influence the chance of a patient being discussed at a MDT conference [12,18]. National rectal cancer treatment guidelines increasingly call for MDT evaluation, and MDT evaluation in some countries is also linked to economic incentives [19]. Although not mandatory by law, the National guidelines [20] in Sweden state that all patients with rectal cancer should be discussed at an MDT conference. We took advantage of the Swedish ColoRectal Cancer Register (SCRCR) to study predictors of discussion at a MDT conference, and to assess whether or not MDT evaluation influences treatment decision-making.

Material and methods

The SCRCR was started in 1995 and is now estimated to have > 99% coverage based on cross- validation with the population-based Swedish Cancer Register, where double registration of all cancer diagnoses by a clinician and a pathologist is mandatory by law. Data on MDT conference discussions have been included in the SCRCR since 2007. This study was based on rectal cancer patients diagnosed between January 2007 and December 2010. All patients who underwent elective surgery for rectal cancer were eligible for the study, and 6760 patients were identified. Patients with metastases at diagnosis and cases with missing data were excluded, leaving 4883 patients for the analysis of factors influencing if the patient were discussed at a preoperative MDT meeting (Figure 1).

Figure 1. Patient inclusion and causes for exclusion in the different subsets.

Factors associated with application of radiotherapy were studied in patients who had undergone elective tumour resection [anterior resection, abdomino-perineal excision (APE) or Hartmann's procedure] with for pT3c, pT3d, pT4 tumours (n = 1043) or for lymph node-positive (pN+) tumours (n = 1991) (Figure 1). To include the whole effect of the MDT on the accuracy of treatment, both including interpreting the MRI correctly and making a correct decision from the interpretation, pathological stages rather than the clinical stages were used for these analyses. The main focus in the analysis of factors associated with preoperative radiotherapy was to assess if there was an association between MDT and use of preoperative radiotherapy. Since age and co-morbidity could be valid reasons for diverging from the recommendations those factors were included in the analysis.

To evaluate if MDT was associated with radiotherapy overtreatment, an analysis of cT1-T2 cN0 patients undergoing anterior resection (n = 500) was made.

Statistical analysis

To determine variables that influence whether or not a patient is discussed at a preoperative MDT conference, patient- and system-related factors were analysed with MDT discussion as outcome variable. In the determination of variables that influence the use of preoperative radiotherapy, patient- and system-related factors were analysed with radiotherapy as outcome variable. Separate analyses were performed for pT3c-T4 tumours and pN+ tumours. Age was divided into quartiles (below median age, third quartile and fourth quartile) based on the age distribution in the initial cohort before exclusions. Hospital volume, i.e. the number of rectal cancer surgery procedures performed annually, was divided according to quartiles; very low volume (≤ 114 cases in 4 years), low volume (115–166 cases in 4 years), medium volume (167–226 cases in 4 years) and high volume (above the third quartile, i.e. > 226 cases). Although the number of ASA grade 4 patients was small, we separately analysed ASA 4 patients based on clinical differences.

Since preoperative radiotherapy should not be given to patients with highly located T1-T2 tumours without extramural vascular invasion (EMVI) and N0 status regardless of co-morbidity or age, MDT was the only independent variable in this analysis with preoperative radiotherapy as outcome variable.

Proportions were compared using univariate and multivariate logistic regression. In the multivariate analysis, all selected variables where entered at the same time (force entry). Log linear regressions were done to look for possible interactions. All interactions suggested by log linear regression were included in the logistic regression analysis but interactions that were not significant in the logistic regression were excluded from the final model. A p-value < 0.05 was considered statistically significant. Tolerance statistics were calculated for all main effects with values < 0.2 considered to indicate a possible co-linearity problem. All statistical analyses were performed using SPSS^© 15.0 (SPSS Inc. Chicago, IL, USA).

Results

Of the 6760 patients in the SCRCR, 78% (5264 of 6760) were discussed at a preoperative MDT conference. There were 35 patients with missing data on preoperative MDT. Complete preoperative staging strongly correlated with MDT discussion; of patients discussed at a preoperative MDT 96% (5045 of 5264) had a complete preoperative staging (defined as staging of primary tumor, lung and liver) compared to 63% (917 of 1461) of the patients who were not evaluated at a MDT.

Hospital volume, age and tumour stage significantly correlated with MDT evaluation (Table I). Patients operated on at low-volume hospitals (29–42 rectal cancer operations annually) were considerably less likely to be discussed at a MDT conference, showing an odds ratio (OR) of 0.27 (95% CI 0.21–0.36). Patients treated at a very low-volume hospital (< 29 rectal cancer surgeries annually) had an OR of 0.15 (95% CI 0.12–0.20) for MDT evaluation. Tumour stages cT1-T2 was associated with a lower probability of being discussed at a MDT conference with an OR of 0.54 , so was also age in the upper quartile (> 79 years) with an OR of 0.45 and ASA 4 with an OR of 0.52. When adjusting for significant interactions, there was a significant effect of ASA 3, OR 0.65 (95% CI 0.49–0.86) and female gender, OR 1.37 (95% CI 1.04–1.82). The effect of tumour stages cT1-T2 were no longer significant when adjusting for significant interactions, OR 0.76 (95% CI 0.56–1.03). For the remaining factors adjustment for significant interactions had minimal influence on the results.

Table I. Factors associated with preoperative MDT conference (n = 4883).

	n MDT/Total	Univariate analysis		p-value	Multivariate analysis		p-value
		OR	CI 95%		OR	CI 95%
Hospital volume
Very low	784/1175 (67%)	0.15	0.12–0.19	< 0.001	0.15	0.12–0.20	< 0.001
Low	1036/1303 (80%)	0.29	0.22–0.38	< 0.001	0.27	0.21–0.36	< 0.001
Intermediate	1107/1190 (93%)	1.00	REF		1.00	REF
High	1124/1200 (94%)	1.11	0.80–1.53	0.529	0.99	0.71–1.38	0.944
Unknown	12/15 (80%)	0.30	0.08–1.09	0.066	0.55	0.14–2.18	0.395
ASA grade
1	826/976 (85%)	0.86	0.70–1.06	0.157	0.84	0.66–1.06	0.135
2	2113/2443 (86%)	1.00	REF		1.00	REF
3	801/954 (84%)	0.82	0.66–1.01	0.058	0.82	0.65–1.04	0.098
4	46/63 (73%)	0.42	0.24–0.75	0.003	0.52	0.28–0.99	0.045
Unknown	277/447 (62%)	0.25	0.20–0.32	< 0.001	0.33	0.26–0.43	< 0.001
Age (years)
< 72	2284/2646 (86%)	1.00	REF		1.00	REF
72–79	1031/1223 (84%)	0.85	0.70–1.03	0.096	1.01	0.81–1.25	0.928
> 79	748/1014 (74%)	0.45	0.37–0.53	< 0.001	0.60	0.48–0.74	< 0.001
Gender
Woman	2398/2874 (83%)	0.96	0.83–1.12	0.606	0.98	0.83–1.17	0.825
Man	1665/2009 (83%)	1.00	REF		1.00	REF
Tumour stage
I–II	1091/1300 (84%)	0.59	0.48–0.73	< 0.001	0.54	0.43–0.67	< 0.001
III	1845/2055 (90%)	1.00	REF		1.00	REF
IV	707/780 (91%)	1.10	0.83–1.46	0.495	1.12	0.83–1.51	0.461
Unknown	420/748 (56%)	0.15	0.12–0.18	< 0.001	0.16	0.13–0.20	< 0.001

Patients with metastasis or with relevant data missing are excluded (Figure 1). The multivariate analysis is adjusted for hospital volume, ASA grade, age, gender and tumour stage but not for interactions. ASA, American Society of Anaesthesiologists; CI 95%, confidence interval of 95%; MDT, multidisciplinary team meeting; OR, odds ratio. Lowest tolerance statistic 0.650.

Preoperative MDT conference discussions were associated with a higher likelihood of treatment with preoperative radiotherapy. This applied to patients with pT3c, pT3d and pT4 tumours as well as to those with pN+ tumours (Tables II and III). In the pT3c-pT4 subset, MDT conference discussion was associated with an increased likelihood of preoperative radiotherapy with an OR of 5.06 (95% CI 3.08–8.34). Age and co-morbidity were associated with a lower use of radiotherapy; OR 0.47 for patients aged 72–79 years, OR 0.20 for patients > 79 years, OR of 0.55 for patients with ASA grade 3 and OR of 0.28 for patients with ASA grade 4. Low-volume hospitals had a more frequent use of preoperative radiotherapy in the multivariate but not in the univariate analysis (Table II). Among patients with pN+ tumours, MDT evaluation was associated with an increased chance of radiotherapy with an OR of 3.55 (95% CI 2.60–4.85). Age and co-morbidity also affected the use of radiotherapy with an OR of 0.57 in the age group 72–79 years, 0.16 in the age group > 79 years and OR 0.60 among patients with ASA grade 3. Hospitals with very low volume had a less frequent use of preoperative radiotherapy in the univariate but not in the multivariate analysis (Table III). In both subsets APE was associated with a more frequent preoperative radiotherapy use (Tables II and III). Apart from an effect in patients with ASA 3 and patients in the age group 72–79 years, in the pT3c-pT4 subset, adjustment for interactions had a minimal influence on the results. The effect of interactions in the analysis of patients with pN+ tumours was not possible to determine since they included higher order interactions.

Table II. System- and patient-related factors in relation to preoperative radiotherapy (pT3c, pT3d and pT4 tumours, n = 1043).

	n RT/Total	Univariate analysis		p-value	Multivariate analysis		p-value
		OR	CI 95%		OR	CI 95%
MDT
Yes	729/939 (78%)	4.38	2.89–6.64	< 0.001	5.06	3.08–8.34	< 0.001
No	46/104 (44%)	1.00	REF		1.00	REF
Hospital volume
Very low	153/224 (68%)	0.77	0.52–1.15	0.202	1.21	0.76–1.94	0.428
Low	212/271 (78%)	1.29	0.86–1.93	0.226	2.03	1.28–3.22	0.003
Intermediate	179/243 (74%)	1.00	REF		1.00	REF
High	231/395 (76%)	1.12	0.76–1.64	0.578	1.02	0.66–1.56	0.939
Missing	0/0
ASA grade
1	152/188 (81%)	1.17	0.77–1.76	0.467	0.90	0.57–1.41	0.631
2	460/587 (78%)	1.00	REF		1.00	REF
3	143/239 (60%)	0.41	0.30–0.80	< 0.001	0.55	0.38–0.79	0.001
4	7/7 (50%)	0.28	0.10–0.80	0.276	0.28	0.08–0.90	0.033
Missing	13/15 (87%)	1.80	0.40–8.06	0.445	5.10	0.98–26.42	0.052
Age (years)
< 72	513/612 (84%)	1.00	REF		1.00	REF
72–79	178/258 (69%)	0.43	0.31–0.60	< 0.001	0.47	0.32–0.69	< 0.001
> 79	84/173 (49%)	0.18	0.13–0.26	< 0.001	0.20	0.13–0.31	< 0.001
Operation type
AR	330/451 (73%)	1.00	REF		1.00	REF
APE	311/370 (84%)	1.93	1.37–2.74	< 0.001	2.57	1.75–3.79	< 0.001
HA	134/222 (60%)	0.56	0.40–0.79	0.001	0.92	0.62–1.36	0.670

Patients with emergency resections or with relevant data missing are excluded (Figure 1). The multivariate analysis is adjusted for MDT, hospital volume, ASA grade, age and operation type but not for interactions. APE, abdominoperineal excision; AR, anterior resection; ASA, American Society of Anaesthesiologists; CI 95%, confidence interval of 95%; HA, Hartmann's procedure; MDT, multidisciplinary team meeting; OR, odds ratio; RT, preoperative radiotherapy (any kind). Lowest tolerance statistic 0.608.

Table III. System- and patient-related factors in relation to preoperative radiotherapy (N1 and pN2 tumours, n = 1991).

	n RT/Total	Univariate analysis		p-value	Multivariate analysis		p-value
		OR	CI 95%		OR	CI 95%
MDT
Yes	1283/1706 (75%)	3.83	2.96–4.96	< 0.001	3.55	2.60–4.85	< 0.001
No	126/285 (44%)	1.00	REF		1.00	REF
Hospital volume
Very low	320/506 (63%)	0.62	0.47–0.81	0.001	0.95	0.69–1.31	0.732
Low	397/552 (72%)	0.92	0.70–1.21	0.558	1.18	0.87–1.61	0.286
Intermediate	345/469 (74%)	1.00	REF		1.00	REF
High	347/464 (75%)	1.07	0.80–1.43	0.669	0.90	0.66–1.24	0.530
Missing	0/0
ASA grade
1	335/440 (76%)	1.16	0.90–1.50	0.248	0.84	0.63–1.12	0.228
2	809/1104 (73%)	1.00	REF		1.00	REF
3	217/381 (57%)	0.48	0.38–0.62	< 0.001	0.60	0.45–0.79	< 0.001
4	10/20 (50)	0.37	0.15–0.89	0.026	0.40	0.14–1.11	0.079
Missing	38/46 (83%)	1.73	0.80–3.76	0.164	3.10	1.31–7.34	0.010
Age (years)
< 72	953/1192 (80%)	1.00	REF		1.00	REF
72–79	332/479 (69%)	0.57	0.45–0.72	< 0.001	0.57	0.43–0.74	< 0.001
> 79	124/320 (39%)	0.16	0.12–0.21	< 0.001	0.16	0.12–0.22	< 0.001
Operation type
AR	644/956 (67%)	1.00	REF		1.00	REF
APE	595/717 (83%)	2.36	1.86–3.00	< 0.001	3.13	2.40–4.08	< 0.001
HA	170/318 (53%)	0.56	0.43–0.72	< 0.001	1.09	0.80–1.48	0.608

Patients with emergency resections or with relevant data missing are excluded (Figure 1). The multivariate analysis is adjusted for MDT, hospital volume, ASA grade, age and operation type but not for interactions. APE, abdominoperineal excision; AR, anterior resection; ASA, American Society of Anaesthesiologists; CI 95%, confidence interval of 95%; HA, Hartmann's procedure; MDT, multidisciplinary team meeting; OR, odds ratio; RT, preoperative radiotherapy (any kind). Lowest tolerance statistic 0.583.

Separate analysis of patients with cT1-T2 cN0 tumours who underwent anterior resection did not show any significant association to use of radiotherapy (OR 1.14, 95% CI 0.68–1.92).

Discussion

Using the SCRCR, we have demonstrated that hospital volume is a major predictor for the likelihood of being evaluated at a MDT conference. Medium- and high-volume hospitals, defined as units with at least 42 rectal cancer operations annually, did not differ, whereas patients treated at low-volume hospitals had a lower chance of MDT evaluation. Patients treated in hospitals that performed < 29 rectal cancer operations annually had an OR of 0.15 for MDT evaluation (Table I). Low tumour stage (cT1-T2) was associated with a lower likelihood of MDT discussion, also after adjustment for hospital volume. Three hospitals did not have MDT conferences at all, but their effect on the results is negligible since in total they contributed 16 patients only. Age also significantly correlated with the chance for MDT evaluation. Patients older than 79 years of age had half the chance of MDT evaluation (OR of 0.60). Though elderly patients may have significant co-morbidity that may limit the number of treatment options, there are no data suggesting that elderly patients should not be considered for MDT evaluation, particularly in view of the fact that there are now refined treatment options with limited surgical or radiologic side effects [21]. Failure to discuss older patients at a MDT conference has also been observed in other studies [12,18]. In contrast to previous studies, gender did not affect MDT conference evaluation in our series [12].

Swedish guidelines for rectal cancer treatment [20] call for preoperative radiotherapy in patients with T3c, T3d, T4, and/or N+ tumours. Radiotherapy is administered as short-course (5 × 5 Gy) or long-course (2 × 25 Gy) treatment, which in the latter case may be combined with chemotherapy. MDT evaluation was strongly associated with radiotherapy for patients with pT3c-pT4 tumours (OR 5.06) and lymph node positive disease (OR 3.55) even when compensating for age, co-morbidity, hospital caseload and type of operation. Co-morbidity was not clearly related to MDT evaluation, though patients with high age and high ASA grade had a significantly lower probability of receiving preoperative radiotherapy. The pT3c-pT4 group was probably largely represented by T4 tumours considering the downstaging effect of radiation. Some hospitals refer T4 tumours for surgery at specialised centres but perform surgery for T3 tumours. Patients with a correct T4 diagnosis and not discussed at a MDT conference at the referring hospital, might still be discussed at a MDT conference at the receiving hospital. Furthermore, since they have a correct staging, they probably have a higher chance of receiving preoperative radiotherapy. This selection bias could influence the T3c-T4 tumour subset. It would not have an impact on N-stage, however, and similar results were found in the two subsets. We could not account for previous radiotherapy administered for other diseases, such as prostate and gynaecological cancers. However, the number of such cases is probably low, and we find it unlikely that the distribution of such cases would be skewed enough for it to significantly influence our results.

The increased likelihood of having preoperative radiotherapy in the low and very low hospital volume groups when comparing the multivariate and univariate analysis is probably due to the strong effect MDT and MDT being less common in these groups. The more frequent use of radiotherapy for APE was probably due to APE representing a higher proportion of low cancers.

One of the main points of having a preoperative MDT for rectal cancer is to discuss the radiological pictures, mainly the MRI. This possibly leads to a more precise staging, which in turn could give the patient a higher chance of receiving the correct treatment. In this paper we wanted to include the whole effect of the MDT on the accuracy of treatment which both includes interpreting the MRI correctly and making a correct decision from the interpretation. Apart from the down staging effect of radiotherapy (which has been considered in the design of this study) we consider the pathological stage to be the true stage and the preoperative stage an estimation of the stage. From our results we cannot differentiate if the association found between the MDT conference and preoperative radiotherapy is due to an association between the MDT conference and better preoperative staging or better decisions made from the preoperative staging or a combination of those.

The Swedish national guidelines state that highly located T1-T2 rectal tumours without extramural vascular invasion (EMVI) and N0 status should not receive preoperative radiotherapy. Since most of the cT1-2 cN0 patients undergoing anterior resection would fall into this category we used this subset to evaluate possible over treatment from MDT, which could not be identified. We avoided using APE patients in this analysis since they are more likely to have a low cancer and therefore should be given preoperative radiotherapy according to guidelines. Since this is a small subgroup of the whole population who should not be given preoperative radiotherapy the evidence value of this analysis is not so strong and overtreatment could still be a possibility.

In conclusion, the system-related factor hospital volume was the major predictor of MDT conference evaluation. Patients treated at very-low volume hospitals had a 67% chance of MDT evaluation compared to 94% for patients treated at larger units. Recommendations for MDT evaluation are included in national guidelines. In order to increase uptake, active auditing may be needed and strategies should be developed to facilitate MDT evaluation, e.g. using video conferences that improve access and are cost effective [22]. MDT evaluation is also an independent predictor of preoperative radiotherapy. These results provide new evidence that MDT evaluation is a key factor for access to evidence-based treatment, and this stresses the need for further studies on MDT evaluation and cancer treatment.

Figure 2. MDT conference discussion in relation to hospital volume (same exclusion criteria as Table I).

Figure 3. MDT conference discussion in relation to preoperative radiotherapy for T3c-T4 tumours (left) and pN+ tumours (right).

Acknowledgements

The authors are grateful to the organisers of the Gastrointestinal Oncology 2010 Course 2010 during which this work began, to Pia Edenvik for great help in starting up this project, to Linda Hartman for help with Figures 2 and 3 and to the managers of the Swedish ColoRectal Cancer Register for help with access to data.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.