Impact of watching prior to commencement of chemotherapy for metastatic colorectal cancer (mCRC): Findings from the South Australian Clinical Registry (SACR) for mCRC.

Abstract

e14139 Background: The role of chemotherapy in mCRC is firmly established and the option of watchful waiting (WW) has become an alternative rarely considered. Evidence from 2 pivotal studies is conflicting and of an era when only 5FU was available. Outcomes for mCRC have improved because of early detection through surveillance, surgery and more effective chemotherapy drugs. However, there may be a group of patients who are diagnosed early with low volume and asymptomatic disease that may be suitable for a WW plan. Methods: The SACR for mCRC collects data on all patients who have a diagnosis of mCRC established after 1/2/06. We examined cancer characteristics and outcomes of patients who were suitable for chemotherapy but had their treatment delayed by more than 3 months from diagnosis of metastatic disease. Results: Data from 417 mCRC patients who received chemotherapy as first intervention have been entered into the Registry to date. 41 (9.8%) of these patients had chemotherapy commencement delayed by more than 3 months from diagnosis. Median age was 76.7 yrs (range 38-87). Stage at diagnosis is as follows (n); I=2, II=8, III=25 and IV=6. For patients with initial stage I-III disease, median time to recurrence was 1.48 years (range 0.53-7.71). 30% and 32.4% had single site lung or liver metastasis respectively. Median delay from diagnosis of metastatic disease to chemotherapy was 5.32 months (range 3-28). Average number of lines of subsequent chemotherapy=1.4 (range 1-4) and 5 patients have received anti-EGFR Rx. The median survival for this group from diagnosis was 23.2 months. Survival is equivalent to that reported for the whole group (ASCO GI 2010, #472). Conclusions: WW is a controversial option. We found that almost 10% of all mCRC had a delay in the initiation of chemotherapy consistent with a WW approach. This group was older and was likely to have a single site of metastatic disease. The majority of these patients had metachronous mCRC and low volume disease, suggesting possible diagnosis by surveillance. Despite the treatment delay, the median survival was almost 2 years.