Prolonged survival with unresected pulmonary metastases

Clinical reports of pulmonary metastasectomy for colorectal cancer: a citation network analysis

Introduction:

Pulmonary metastasectomy for colorectal cancer is a commonly performed and well-established practice of ∼50 years standing. However, there have been no controlled studies, randomised or otherwise. We sought to investigate the evidence base that has been used in establishing its status as a standard of care.

Methods:

Among 51 papers used in a recent systematic review and quantitative synthesis, a citation network analysis was performed. A total of 344 publications (the 51 index papers and a further 293 cited in them) constitute the citation network.

Results:

The pattern of citation is that of a citation cascade. Specific analyses show the frequent use of historical or landmark papers, which add authority. Papers expressing an opposing viewpoint are rarely cited.

Conclusions:

The citation network for this common and well-established practice provides an example of selective citation. This pattern of citation tends to escalate belief in a clinical practice even when it lacks a high-quality evidence base and may create an impression of more authority than is warranted.

Clinical trials for pulmonary metastasectomy

There remains great controversy as to the indications and true benefits for pulmonary metastasectomy. The number of metastatic lesions, length of disease-free interval, and unilaterality has shown to be important prognostic factors on overall survival. In this review, we evaluate a number of clinical trials and critically assess the rational to perform pulmonary metastasectomy, which is a local treatment for a systemic disease process.

Sequential thoracic metastasectomy prolongs survival by re-establishing local control within the chest

OBJECTIVE

The value of sequential thoracic metastasectomies is unknown. We evaluate repeat metastasectomy for limited recurrences within the thorax.

METHODS

From July 1988 to September 1998, 54 patients underwent 2 to 6 separate sequential procedures to excise metastases after recurrence isolated to the thorax. Kaplan-Meier survival and Cox modeling determined prognostic variables.

RESULTS

Thirty-three men and 21 women, 22 to 76 years underwent 2 (100%, n = 54), 3 (50%), 4 (22%), or 5 to 6 (11%) metastasectomies. Fifty-four percent of patients had carcinoma, 35% sarcoma, 9% germ cell, and 2% melanoma. There were no operative deaths; all late deaths occurred from cancer. Median follow-up was 48 months. Cumulative 5-year survival from the second procedure was 57%. After the second, third, fourth, and fifth procedures, respectively, permanent control was achieved in 15 (27%) of 54 patients, 5 (19%) of 27, 1 (8%) of 12, and 0 of 7. Recurrence amenable to additional surgery occurred in 27 (50%) of 54, 12 (44%) of 27, 6 (50%) of 12, and 1 (17%) of 6. Mean hazard for the development of unresectable recurrence increased from 0.21 after the second procedure to 0.91 after the fifth procedure. The 5-year survival for the 27 patients undergoing only 2 metastasectomies was 60% (median not yet reached), 33% for the 15 patients undergoing only 3 metastasectomies (median 34.7 months), and 38% for the 12 patients undergoing 4 or more (median 45.6 months). From the time a recurrence was declared unresectable, patients had a 19% 2-year survival (median 8 months).

CONCLUSIONS

Multiple attempts to re-establish intrathoracic control of metastatic disease is justified in carefully selected patients, but the magnitude of benefit decays with each subsequent attempt.

Surgery for pulmonary metastases. Who are the 10-year survivors?

BACKGROUND

Surgical resection of pulmonary metastases (PMs) has been shown to produce approximately a 35% 5-year survival rate, but specific data about late survival are not available in the literature.

METHODS

A retrospective review and survival analysis of 186 adult patients who underwent surgery for PMs at a single center before June 1984 is presented.

RESULTS

Of the 186 patients who had surgery, of whom 34 (18%) had an incomplete resection, the 10-year survival rate (Kaplan-Meier) was 23% (95% CI, 16-30%), and 36 patients, with PMs from nine different primary sites, were still at risk at 10 years. Two patients died of their primary disease more than 10 years after the first thoracotomy, and two are alive with uncontrolled disease. Thirty-one patients are currently alive and disease free. Comparison between the 36 10-year survivors and the 150 nonsurvivors revealed that only the percentage of incomplete resections and the mean number of resections per patient were significantly different between the two groups (P < 0.001); the histologic type of the primary tumor, the disease-free interval, and the number of resected PMs at the first thoracotomy were not found to be statistically significant prognostic factors.

CONCLUSIONS

The 23% 10-year survival and the high rate of disease free 10-year survivors in this study constitute support for complete resection as an efficient therapeutic approach in patients with isolated PMs. Relevant criteria to select more precisely those patients who will benefit from resection remain to be developed.