On the need for biopsy confirmation at suspected first recurrence of cancer

At the time of suspected first recurrence of cancer, it is unclear whether biopsy confirmation is routinely performed, although this is a very common clinical situation. First, 20 oncologists were surveyed to ascertain the pattern of practice in our community. A questionnaire with hypothetical typical cases suspected of having recurrent cancer was distributed. Second, eligibility criteria were reviewed from investigational protocols from the National Cancer Institute (NCI) and the Eastern Cooperative Oncology Group to see whether confirmation of recurrence was specifically required in these research studies. Third, 64 cases from our own practice were reviewed retrospectively to determine our patterns and results in performing biopsies to document suspected recurrence. Finally, criteria were developed that might suggest the need for biopsy confirmation of recurrence and then retrospectively tested against our cases. There was no clear consensus among oncologists regarding the need for tissue confirmation in patients with solid tumor with suspected recurrences, although rebiopsy was routinely requested for recurrent lymphoma. Published Eastern Cooperative Oncology Group and NCI protocols reviewed did not require biopsy proof specifically of recurrence. Retrospective review of our own cases suggested that, in the absence of one of the proposed indicators, the risk of making an erroneous diagnosis without biopsy confirmation is low. It is suggested that biopsy is not routinely necessary for confirmation of recurrence in all cases of suspected recurrent solid tumors, but criteria are proposed that would help to reduce the possibility of misdiagnosis when biopsy of suspected recurrence is not performed.