An increasingly common challenge: management of the complete responder with multi-focal metastatic colorectal cancer.

K.A. is a 61-year-old woman diagnosed with a nonobstructing, moderately differentiated adenocarcinoma of the ascending colon in the spring of 2003. At diagnosis, she had palpable left supraclavicular adenopathy that was biopsied and found to be consistent with metastasis of colonic primary tumor. Contrast-enhanced computed tomography (CT) scan of the chest, abdomen, and pelvis revealed wall thickening of the ascending colon as well as diffuse adenopathy in hilar, gastrohepatic, retroperitoneal, para-aortic, mesenteric, and iliac regions. Pretreatment fluorodeoxyglucose positron emission tomography (FDG PET) scan revealed diffuse uptake in these multiple nodal stations but no evidence of pulmonary or hepatic involvement. The patient was a widowed administrator for a nursery school program and had no notable past medical history and an unremarkable family history. When the patient presented for medical oncology opinion in June 2003, she had intermittent, mild, crampy abdominal pain, no melena or bright red blood per rectum, and was able to tolerate a low residue diet. She had experienced an 8-lb unintentional weight loss but denied fevers, chills, or sweats. She was informed that treatment options for stage IV colon cancer are palliative rather than curative, with median survival estimated at 20 months based on recent clinical trials. The FOLFOX6 regimen, consisting of biweekly fluorouracil, leucovorin, and oxaliplatin, was recommended. With initiation of treatment, her abdominal cramping improved, and the left supraclavicular lymph node was no longer palpable after three cycles. Treatment was administered for five cycles, and first interval restaging CT scan indicated dramatic response. Treatment was continued for five more cycles, and the second restaging revealed persistence of the colonic primary and stable adenopathy (Fig 1B). The patient was able to continue work during treatment and experienced transient neutropenia, fatigue, nausea, and mild neuropathy. Although she tolerated therapy well, because comparison of her first and second interval CT scans suggested that her response to FOLFOX had reached a plateau, she was referred to a colorectal surgeon for consultation regarding the possibility of resection of the primary tumor. To further evaluate the extent of residual tumor, PET scan was obtained and revealed persistent uptake in the ileocecal region (standardized uptake value 4.0) primary, but no evidence of increased uptake in areas corresponding to the multifocal adenopathy appreciated on the pretreatment PET scan. In January 2004, the patient opted for surgery despite both the surgeon and the oncologist’s caution that there is no compelling evidence base to suggest that resection of the primary tumor in this circumstance provides survival advantage. At exploratory laparotomy, stricture of the ascending colon was appreciated, and an extended right hemicolectomy with resection of mesentery and regional lymph nodes was performed. Gross pathologic examination revealed an ulcerated firm lesion in the proximal ascending colon that, under microscopic examination, consisted of transmural fibrosis and inflammation associated with surface ulceration. Sixteen regional lymph nodes were recovered, and all 16 were negative for metastasis. No residual viable tumor was identified in the entire resection specimen (Figs 2C and 2D). Thus, this patient with pathologically confirmed distant disease has a surgically confirmed complete response to 10 cycles of FOLFOX therapy. JOURNAL OF CLINICAL ONCOLOGY COMMENTS AND CONTROVERSIES VOLUME 23 NUMBER 9 MARCH 2