Author(s): Marc Paul J. Lopez, M.D.; John Paul S. Gonzalez, M.D.; Mark Francis A. Melendres, M.D.; Manuel Francisco T. Roxas, M.D., F.P.C.S.; Marie Dione A. Parreño-Sacdalan, M.D.; Hermogenes J. Monroy III, M.D., F.P.C.S.; Armando C. Crisostomo, M.D., F.P.C.S. and Alberto B. Roxas, M.D., F.P.C.S. for the UP-PGH Colorectal Cancer and Polyp Study Group
The study aimed to document the pathologic complete response (pCR) rates at the Philippine General Hospital (PGH) from 2005 to 2009. The response to neoadjuvant chemoradiotherapy as evidenced by tumor downstaging was also documented.
The study included all adult patients with low to mid rectal tumors, described as tumors with distal extent 11 cm or below from the anal verge (FAV), who underwent resection after having undergone preoperative chemoradiotherapy. Patients who underwent surgery from January 1, 2005 to December 31, 2011 were included. Data pertinent to response to neoadjuvant chemoradiotherapy were collected. Frequencies and rates pertaining, particularly those relating to pCR and tumor downstaging, were computed.
There were a total of 204 rectal resections for cancer over a seven-year period. The patients’ mean age was 52.7 years (range: 22 to 83). There were 168 males and 136 females (ratio 1.2:1). Fifty-three percent of patients presented with clinical Stage IIIB. One hundred fifty-five (41%) patients underwent either preoperative radiotherapy (14.15%, n=43) or combined chemoradiotherapy (36.82%, n=112). Of those who underwent long course chemoradiotherapy (LCCRT), 60.7 percent of tumors were down staged. Twenty-one percent of tumors had a pCR. Among patients with a pCR, the mean age was 47.22 years (range 23-72 years). The average distance FAV was 5.7 cm (range 3-10 cm). Majority presented with clinical stage IIIB (66.7%), and nearly all (95.8%) underwent a sphincter-saving operation.
Conclusion: The utilization of neoadjuvant chemoradiation in our setting has shown comparable outcomes to those reported in foreign literature on rates of downstaging and pCR. A more protracted study should be pursued to assess for long-term outcomes regarding recurrence and survival.
Key words: rectal cancer, pathologic response, combined modality therapy