HOW BAD IS A WHOOPS PROCEDURE? – ANSWERS FROM A CASE MATCHED SERIES

Abstract

Introduction: A ‘whoops’ procedure is when a lump, which subsequently turns out to be a soft tissue sarcoma (STS), is shelled out by a surgeon who is not aware of the diagnosis. In many cases residual tumour will be left behind necessitating further surgery. The significance of a whoops procedure in terms of survival and local control remains uncertain. This study has used case matched controls to compare outcome between two groups.

Method: 794 patients of soft tissue sarcoma with minimum follow up of 5 years were found on our prospectively collected database. 113 were whoops cases, 96 had restaging and reexcision. An observer blinded to the outcome of patients matched the whoops cases with virgins by known prognostic factors i.e. grade, depth, patient age, site, size and diagnosis of the tumour. We have investigated outcome in terms of local control, metastatic disease and survival by known prognostic factors and by their status at presentation.

Results: 96 patients with a whoops procedure were compared with 96 referred directly to our unit. Despite attempts to match patients with as many variables as possible there was a tendency for the patients with whoops to have smaller tumours that were subcutaneous, they were however well matched for grade and stage at diagnosis. 64% of whoops patients had adequate final margin whereas only 44% of virgins had adequate margins. Overall 1.43 additional operations were needed to achieve final margins for whoops cases as against 0.21% for virgin cases. Overall 27% patients had amputation 20% for whoops and 34% for virgin cases nearly 60% were ray amputations of foot or hand. Overall 50% had radiotherapy and 25% had chemotherapy. There was no statistical difference in local recurrence or survival of patients between whoops and virgins at 5 years follow up. Inadequate margins and residual tumour were significant risk factors for local recurrence and high grade, size more than 5 cm, and age more than 50 years were significant prognostic factors for overall survival of the patients.

Conclusion: Inadvertent surgical excision of a STS is not desirable but does not seem to lead to an adverse outcome in this series in which wide re-excision of the area involved has been carried out.