TN Disease Category Impacts Outcomes in Anal Cancer Patients

ORLANDO, FL—The TN category of disease has a significant impact on survival, relapse, and colostomy failure in patients with anal cancer treated with concurrent chemoradiation (CCRT), according to an analysis of the US GI Intergroup RTOG 98-11 study reported at the 2010 Gastrointestinal Cancers Symposium by L.L. Gunderson, MD, of the Mayo Clinic in Phoenix, Arizona.

In particular, the TN was found to be associated with significant outcomes in overall survival (OS), disease-free survival (DFS), local-regional failure (LRF), distant metastases (DM), and colostomy failure (CF).

RTOG 98-11 evaluated CCRT with 5-FU plus mitomycin versus 5-FU plus cisplatin, and found that colostomy-free survival was improved with the 5-FU plus mitomycin regimen. The current analysis aimed to determine the impact of TN category on numerous clinical outcomes.

Investigators evaluated 6 TN categories for their association with outcomes in 615 patients. According to Gunderson, “All endpoints showed significant differences between TN categories of disease.” OS, DFS, LRF, and DM were not statistically different for T2N0 and T3N0, but they were worse for the other TN categories.

The poorest OS, DFS, and LRF were observed in T3-4N patients. Outcomes were similar for T2N patients and T4N0 patients. In the node-negative group, OS at 5 years was 81% for T2, 75% for T3, and 59% for T4, and DFS was 69%, 63%, and 40%, respectively. In the node-positive group (1-3 nodes), OS at 5 years was 66% for T2, 44% for T3, and 48% for T4. DFS was 50%, 33%, and 14%, respectively, reported Gunderson.

At 5 years, distant metastases occurred in 12% of T2N0 patients compared with 31% of T2N patients. Colostomy failure at 3 years was not affected by TN category in patients receiving 5-FU plus mitomycin, ranging from 2% to 20%, but on the 5-FU plus cisplatin regimen it was significantly greater in the T4N0 (37%) and T3N (28%) categories.

“Significant challenges remain for patients with T4N0 disease and patient with node-positive disease,” Gunderson said. “Potential strategies to improve outcomes include treatment intensification and molecular-based individualized treatment.”

2010 GI Symposium Abstract 285