Pathological complete response and sphincter-sparing surgery after neoadjuvant radiochemotherapy with regional hyperthermia for locally advanced rectal cancer compared with radiochemotherapy alone

Figures & data

Table I.  Grades of tumour regression according to Becker's regression scale.

Grade	Degree of regression
1a	Pathological complete response (pCR)
1b	<10% morphologic intact tumour cells
2	10–50% morphologic intact tumour cells
3	>50% morphologic intact tumour cells

Table II.  Patients and tumour characteristics.

	RCT group	HRCT group (all patients)	HRCT group (1–3 treatments)	HRCT group (>4 treatments)	p
Number of patients	45	61	21	40
Age					NS
Mean (years)	68	64	66	67
Range (years)	43–87	38–89	42–89	38–83
Sex					NS
Male	31 (69%)	34 (56%)	13 (62%)	21 (52.5%)
Female	14 (31%)	27 (44%)	8 (38%)	19 (47.5%)
Tumour distance from anal verge					0.007
Mean (cm)	7.54	5.87	5.86	6.18
Clinical stage					NS
T3N0	7 (16%)	10 (16%)	4 (19%)	6 (15%)
T3N+	31 (69%)	46 (75%)	15 (71%)	31 (77.5%)
T4N0	1 (2%)	1 (2%)	1 (5%)	0 (0%)
T4N+	6 (13%)	4 (7%)	1 (5%)	3 (7.5%)
Tumour grade					NS
G1	3 (7%)	8 (13%)	3 (14%)	5 (12.5%)
G2	36 (80%)	47 (77%)	16 (76%)	31 (77.5%)
G3	6 (13%)	6 (10%)	2 (10%)	4 (10%)

HRCT, hyperthermia plus radiochemotherapy; RCT, radiochemotherapy; NS, statically not significant; p values compare the RCT group with the HRCT (all patients) group.

Figure 1. Distribution of tumour regression grades after preoperative radiochemotherapy without pelvic hyperthermia (RCT), with 1–3 hyperthermia treatments (HRCT 1–3) and with four or more hyperthermia treatments (HRCT > 4). With the application of at least four hyperthermia treatments significantly more patients achieved pathological complete response (see Table I).

Table III.  Clinical (pretreatment) and pathological tumour stages.

	RCT	HRCT (all patients)	HRCT (1–3 treatments)	HRCT (>4 treatments)
cT3cN0
ypT0ypN0	1	1	0	1
ypT1ypN0	0	1	0	1
ypT1ypN+	0	1	0	1
ypT2ypN0	2	2	1	1
ypT3ypN0	3	3	1	2
ypT3ypN+	1	2	2	0
cT3cN+
ypT0ypN0	2	9	1	8
ypT0ypN+	2	1	1	0
ypT1ypN0	2	1	1	0
ypT2ypN0	9	10	4	6
ypT2ypN+	1	3	1	2
ypT3ypN0	10	12	5	7
ypT3ypN+	3	9	1	8
ypT4ypN0	1	0	0	0
ypT4ypN+	1	1	1	0
cT4cN0
ypT3ypN+	1	0	0	0
ypT3ypN0	0	1	1	0
cT4cN+
ypT1ypN0	1	0	0	0
ypT2ypN0	1	0	0	0
ypT2ypN+	0	1	1	0
ypT3ypN0	2	2	0	2
ypT3ypN+	1	1	0	1
ypT4ypN+	1	0	0	0

RCT, neoadjuvant radiochemotherapy; HRCT, neoadjuvant radiochemotherapy with pelvic hyperthermia.

Table IV.  Tumour regression grades and hyperthermia related parameters.

	Tumour regression grade				p
	1a (pCR)	1b	2	3
Number of patients	10	20	20	11
Mean CEM T43 (min)	2.045	1.54	1.47	2.59	NS
Mean T90 (°C)	39.26	39.22	39.22	39.58	NS
Mean haemoglobin (mg/dL)	13.86	12.73	13.87	12.95	NS

pCR, pathological complete response; T₉₀, temperature achieved in 90% of tumour-related measurement points; CEM T43, cumulative equivalent min at 43°C.