Proposal of a Useful Surrogate Endpoint of the Overall Survival in Patients Undergoing Pulmonary Metastasectomy: The Time to Local Therapy Failure

Time to Incurable Recurrence for Patients Treated With Pulmonary Metastasectomy for Colorectal Cancer

BACKGROUND

Probability of cure is important for patients with lung metastasis who must decide whether to undergo metastasectomy. Although progression-free survival (PFS) is thought to reflect this, it does not include curative effects by repeat metastasectomy. Thus, the authors developed a new indicator, time to incurable recurrence (TTIR), in which only incurable recurrence was set as an event that included death, with incurable recurrence defined as recurrence not treated by definitive local therapy (DLT), recurrence treated by DLT but with PFS maintained less than 2 years, or recurrence followed by re-recurrence.

METHODS

This multi-institutional study included 339 patients who underwent lung metastasectomy for colorectal cancer between 1990 and 2008.

RESULTS

Among the 339 patients, 191 experienced recurrence, 77 received DLT for recurrence, 38 had a PFS of 2 years or longer after the treatment, and 33 had maintained a PFS at the last follow-up date. The patients had PFS ranging from 39 to 212 months (median, 101 months). The 5-year OS, PFS, and TTIR rates were respectively 63.4%, 42.2%, and 51.9%. The TTIR curve was similar to the OS curve 7 years after the initial metastasectomy. The difference between TTIR and PFS at 7 years was 9.7%, indicating probability of cure by repeat DLT. Multivariable analysis showed different prognostic factors among OS, PFS, and TTIR.

CONCLUSION

At the initial metastasectomy, TTIR may reflect probability of a cure, including cure by repeat DLT, and can be used to analyze prognostic factors associated with cure.

Results of redo pulmonary metastasectomy

Repeat surgical resection (redo) for pulmonary metastases is a questionable, albeit intriguing topic. We performed an extensive review of the literature, to specifically analyze results of redo pulmonary metastasectomies. We reviewed a total of 3,523 papers. Among these, 2,019 were excluded for redundancy and 1,105 because they were not completely retrievable. Out of 399 eligible papers, 183 had missing information or missing abstract, while 96 lacked data on survival. A total of 120 papers dated from 1991 onwards were finally included. Data regarding mortality, major morbidity, prognostic factors and long-term survivals of the first redo pulmonary metastasectomies were retrieved and analyzed. Homogeneity of data was affected by the lack of guidelines for redo pulmonary metastasectomy and the risks of bias when comparing different studies has to be considered. According to the histology sub-types, redo metastasectomies papers were grouped as: colorectal (n=42), sarcomas (n=36), others (n=20) and all histologies (n=22); the total number of patients was 3,015. Data about chemotherapy were reported in half of the papers, whereas targeted or immunotherapy in 9. None of these associated therapies, except chemotherapy in two records, did significantly modify outcomes. Disease-free interval before the redo procedure was the prevailing prognostic factor and nearly all papers showed a significant correlation between patients’ comorbidities and prognosis. No perioperative mortality was reported, while perioperative major morbidity was overall quite low. Where available, overall survival after the first redo metastasectomy ranged from 10 to 72 months, with a 5-years survival of approximately 50%. The site of first recurrence after the redo procedure was mainly lung. Despite the data retrievable from literature are heterogeneous and confounding, we can state that redo lung metastasectomy is worthwhile when the lesions are resectable and the perioperative risk is low. At present, there are no “non-surgical” therapeutic options to replace redo pulmonary metastasectomies.