“Watchful waiting” for metastatic colorectal cancer, antediluvian or an option to be considered again?

Abstract

The role of chemotherapy in metastatic colorectal cancer (mCRC) is firmly established and the option of watchful waiting (WW) has become an alternative rarely considered. However, there may be a group of patients who are diagnosed with low volume and asymptomatic disease and who may be suitable for a WW plan. From the South Australian Cancer Registry for mCRC 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. Data from 417 mCRC patients who received chemotherapy as first intervention have been entered in the Registry to date and 38 (9.1%) had chemotherapy commencement delayed by more than 3 months from diagnosis. Their median age was 76.7 years (range 38-85). Overall 87% of patients had metachronous metastatic cancer with a median time to recurrence of 2.1 years (range 0.53-7.71) and 65.5% had single organ metastasis. Median delay from the diagnosis of metastatic disease to chemotherapy was 5.03 months (range 3-28). The median survival has yet to be reached. The 2-year overall survival is 65%. We found that almost 10% of all patients with mCRC had a delay in the initiation of chemotherapy, with most due to a WW approach based on case note review. Patients with a delay in chemotherapy initiation are more likely to have a single organ site of metastatic disease and are older than those who do not. Despite the treatment delay, there is no evidence of a negative impact on survival.