NEW YORK (Reuters Health) – A Dutch population-based study has shown that, while mucinous colorectal cancer is thought to carry a poor prognosis, it actually responds as well to adjuvant chemotherapy as nonmucinous CRC.
“Therefore, current adjuvant treatment recommendations should not take histology into account,” the researchers advise.
In the background to their report, they explain that the prognostic significance of mucinous colorectal carcinoma is controversial. Mucinous carcinoma often presents at a more advanced stage and adjuvant chemotherapy is indicated for many patients. However, in the palliative setting, metastatic mucinous carcinoma is seen to be less responsive to chemotherapy.
To clarify the picture, Dr. Niek Hugen, at Radboud University Nijmegen Medical Centre, and colleagues examined data in the Eindhoven Cancer Registry on 27,251 unselected CRC patients diagnosed between 1990 and 2010.
As reported in the Annals of Oncology published online September 24, 12.3% of the cases were mucinous carcinoma. Regarding distribution, mucinous carcinoma was less often located in the rectum (24.4%) than was nonmucinous carcinoma (38.0%), but more often in the proximal colon (54.3% versus 30.6%).
When the cancer occurred in the rectum, overall survival at 5 years was significantly lower for patients with mucinous carcinoma (41.0%) than for those with nonmucinous disease (51.2%), which translated to a hazard ratio of 1.22 (p<0.0001). There was no difference in overall survival between mucinous and nonmucinous carcinoma located in the colon.
Adjuvant chemotherapy for stage III disease was administered to 48.8% of patients with mucinous disease and 50.9% of those with nonmucinous histology. Median overall survival in all patients who received chemotherapy was 133 months, compared to 33 months among who were not treated.
In the stage III subgroup of patients who underwent adjuvant chemotherapy, mucinous versus nonmucinous histology was not an independent prognostic survival factor (hazard ratio 1.05), Dr. Hugen and colleagues found.
“We have shown that MC (mucinous carcinoma) seems to have no impact on survival, except when located in the rectum,” they conclude. “Therefore, current adjuvant treatment recommendations should be adhered to regardless of tumor type.”
SOURCE: Prognosis and value of adjuvant chemotherapy in stage III mucinous colorectal carcinoma
