The efficacy of chemotherapy and operation in patients with colorectal neuroendocrine carcinoma.

BACKGROUND

Colorectal neuroendocrine carcinoma (CRNEC) is a rare type of malignancy and is quite aggressive with dismal prognosis. Neither large-scale retrospective studies nor prospective studies have been performed to evaluate the prognostic value of adjuvant chemotherapy in patients with CRNEC.

METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare database, 318 elderly patients who were diagnosed with high-grade colorectal neuroendocrine tumors were included. The survival benefit was evaluated using a Cox proportional hazards model and propensity score-matched techniques.

RESULTS

Among patients with stage I-III CRNEC, there was also no significant difference in cancer-specific survival (CSS) (P = 0.898) or overall survival (OS) (P = 0.539) between the 5-fluorouracil (5-FU) and the no chemotherapy groups. Meanwhile, the etoposide + platinum (EP) regimen showed no improved survival in patients with stage I-III CRNEC compared with the no chemotherapy group. For stage IV CRNEC, there was no significant difference between operation group and no operation group in CSS (P = 0.317) or OS (P = 0.385). Both 5-FU and EP regimens improved the CSS (for 5-FU, hazard ratio [HR] = 0.257, 95% confidence interval [CI] = 0.134-0.491, P < 0.001; for EP, HR = 0.348, 95% CI = 0.192-0.631, P = 0.001) and OS (for 5-FU, HR = 0.274, 95% CI = 0.149-0.502, P < 0.001; for EP, HR = 0.345, 95% CI = 0.194-0.612, P < 0.001) of patients in stage IV CRNEC.

CONCLUSIONS

Our findings demonstrated that neither the 5-FU based nor EP chemotherapy regimens improved the CSS or OS for patients with stage I-III CRNEC. And for stage IV CRNEC, chemotherapy is an independent prognostic factor for CSS and OS, while operation could not improve the CSS or OS for patients with stage IV CRNEC.