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

ABSTRACT

PURPOSE: To evaluate the influence of regional hyperthermia on rates of complete pathological response (pCR) and sphincter-sparing surgery in the context of an up-to-date radiochemotherapy protocol for locally advanced rectal cancer. METHODS: Between 2007 and 2010, 106 patients with locally advanced cancer of the middle and lower rectum were admitted to neoadjuvant radiochemotherapy either with (n = 61) or without (n = 45) regional hyperthermia. A retrospective comparison was performed between two groups 45 patients received standard treatment consisting of 5040 cGy in 28 fractions to the pelvis and 5-fluorouracil (RCT group) and 61 patients received the same treatment in combination with regional hyperthermia (HRCT group). Target temperature was 40.5°C for at least 60 min. Total mesorectal excision was performed routinely. RESULTS: pCR was seen in 6.7% of patients in the RCT group and 16.4% in the HRCT group. Patients who received at least four hyperthermia treatments (n = 40) achieved a significantly higher pCR rate (22.5%) than the remaining 66 patients (p = 0.043). Rates of sphincter-sparing surgery were similar in both groups with 64% in the RCT group and 66% in HRCT. When considering only low-lying tumours located within 8 cm of the anal verge prior to treatment, the rate of sphincter-sparing surgery was 57% in the HRCT group compared with 35% in the RCT group (p = 0.077). CONCLUSION: The combination of regional hyperthermia and neoadjuvant radiochemotherapy may lead to an increased pCR rate in locally advanced rectal cancer. Patients with low-lying tumours especially may benefit when additional downsizing allows sphincter-preserving surgery.