Primary rectal carcinoma in patients with stage IV resectable disease at diagnosis

Rectal cancer is commonly diagnosed at a precocious stage, but for patients presenting at diagnosis with stage IV disease the best treatment is still undefined. The purpose of this study was to review the feasibility and outcome of multimodality treatment of rectal cancer patients metastatic at diagnosis.

From January 2000 to December 2005, 40 patients with histologically proven stage IV rectal adenocarcinoma (< 12 cm from the anal verge) were examined. Variables considered were age (under or over 65 years), tumour grade, presence of peritoneal carcinomatosis, type of surgery (palliative versus resection).

The median age was 61 years (range, 32-83) and 27 were male and 13 female. Seventeen patients with unresectable or potentially resectable metastatic disease received neoadjuvant chemoradiotherapy (CHT-RT) with 5-fluorouracil (5FU) (plus oxaliplatin in 11 cases), radical surgery was performed in almost half of the cases; only in two patients were metastases also resected. If the patient is a candidate for radical surgical resection, the primary tumour should initially be treated as in a patient without metastatic disease and subsequently the primary tumour and metastases should be treated surgically. If the metastases are unresectable, the treatment of the primary lesion, according to the patient's symptoms, should be by palliative CHT. It is still not determined whether RT should be reserved for the symptomatic cases as an alternative to local surgery. In five patients treated with neoadjuvant CHT alone, radical local surgery was performed in two cases. Eighteen symptomatic patients were resected primarily; all of them received a postoperative CHT but only five of them also received postoperative RT. Nevertheless, after a multimodality treatment (neoadjuvant CHT +/- RT) 22.5% achieved a response rate (RR) (one complete remission (CR) and eight partial remission (PR)). Considering that all except two of the patients were locally radically resected and two of them also underwent metastases surgery, the overall RR was 17.5% (four CR and three PR). All of the CR were disease-free and alive after a median follow-up of 19.3 months. Age > or = 65 years had no impact on overall survival (OS), but the presence of peritoneal carcinosis in five patients showed a trend towards diminished survival, although it was not statistically significant (p = 0.08).

The best treatment on diagnosis of metastatic rectal cancer is a multimodality CHT-RT approach. New prospective studies should evaluate non cross-resistant regimens as additional therapy for those patients with a systemic residual disease after common CHT-RT.