Surgical techniques for nonseminomatous germ cell tumors metastatic to the lung

Pulmonary metastasectomy in germ cell tumors and prostate cancer

Pulmonary oligo-metastases and oligo-recurrences are terms used to define a set of clinical conditions consisting of limited metastatic malignant disease characterized by an intermediate aggressive behavior compared to diffuse metastatic conditions. If the primary tumor has been controlled and extra-thoracic lesions are excluded, there is a suggestion in the medical literature that removal of such lesions could potentially prolong survival. The lungs are a common metastatic spreading site, especially from epithelial malignancies and sarcomas; pulmonary surgical or interventional metastasectomy have been proposed with curative intent in case of limited tumor load (usually less than 5 lesions). There are many series reporting data about colorectal, renal or breast lung metastasectomy, but the absence of multi centric prospective trials determines a lack of definitive evidence, especially for less common tumors such as metastatic germ cell and prostate cancer. They rarely present in the oligo-metastatic form and their management is often based on personal experience. The aim of our article is to review the latest evidence in the treatment of pulmonary metastatic germ cell and prostate tumors. We cover the full range of treatments: from surgery to ablative radiotherapy and combination of local and systemic therapy. Despite the absence of evidence based guidelines, it emerges that pulmonary metastasectomy should always be considered when general criteria for resection have been met. In germ cell tumors surgery should be mainly reserved for residual disease after chemotherapy, whereas in prostate cancer, pulmonary metastasectomy should be preferred to avoid or delay hormonal deprivation therapy and its side effects.

Pulmonary Metastasectomy for Germ Cell Tumors

Germ cell tumors (GCTs) are the most common malignancy among young men in the United States. Although prognosis is favorable and response to cisplatin-based chemotherapy regimens is good, 10%–20% of patients with thoracic metastases require surgical management following completion of chemotherapy. Pulmonary metastasectomy (PM) has been employed for GCT patients with lung metastases for several decades. Outcomes have been excellent thus far. However, there have been no randomized controlled trials of PM in GCT and, as new surgical techniques are developed, there is variability in management. This article reviews the existing data on current management of pulmonary metastases in GCT, with attention paid to timing of surgery, surgical approaches, and complications.

Survival after resection for metastatic testicular nonseminomatous germ cell cancer to the lung or mediastinum

BACKGROUND

Since the advent of cisplatin-based chemotherapy, nonseminomatous germ cell tumors (NSGCT) have been considered one of the most curable solid neoplasms and a model for multimodality cancer therapy. We undertook an institutional review of testicular NSGCT patients who underwent operations to remove lung or mediastinal metastases after chemotherapy in the cisplatin era to determine outcomes.

METHODS

From 1980 to 2006, 431 patients underwent 640 postchemotherapy surgical procedures to remove lung (n = 159, 36.8%), mediastinal (n = 136, 31.6%), or both lung and mediastinal (n = 136, 31.6%) metastases within 2 years of chemotherapy. Multiple variables potentially predictive of survival were analyzed.

RESULTS

The overall median survival was 23.4 years, with 295 (68%) patients alive and well after an average follow-up of 5.6 years. There was no survival difference in patients who underwent removal of lung or mediastinal metastases. Pathologic categories of resected residual disease were necrosis (21.5%), teratoma (52.7%), persistent NSGCT (15.0%), and degenerative non-germ cell cancer (10.1%). Multivariable analysis identified older age at time of diagnosis (p = 0.001), non-germ cell cancer in testes specimen (p = 0.004), and pathology of residual disease (p < 0.001) as significantly predictive of survival.

CONCLUSIONS

Patients who undergo resection of residual lung or mediastinal disease for metastatic testicular NSGCT as a planned approach after cisplatin-based chemotherapy have overall excellent long-term survival. Survival is equivalent comparing hematogenous and lymphatic routes of metastases but depends on the pathology of the resected disease. These results justify an aggressive surgical approach, particularly to remove residual teratoma in the lung or mediastinum after chemotherapy, including multiple surgical procedures if necessary.

[The approach to tumors of the retrocrural mediastinum]

Retrocrural tumors of the lower posterior mediastinum are rare. Most tumors in this region involve lymphatic metastasis of germ cell tumors. Formerly these tumors were resected through a combined thoracoabdominal approach, with division of the diaphragm and effecting an at least partial phrenic paresis. The ventral approach via bilateral subcostal incision with cranial extension avoids this problem and allows a bilateral access to the retrocrural space. From November 1999 to December 2005, using this approach we operated on 12 patients with residual germ cell tumors after chemotherapy. In all cases radical resection was obtained. Intra- or postoperative complications did not occur. All patients are still alive and free of disease.

Preoperative Workup and Postoperative Surveillance for Patients Undergoing Pulmonary Metastasectomy

The workup of patients suspected of having pulmonary metastases is complicated by the fact that a high percentage of pulmonary metastases are 6mm or less at presentation. Helical CT scans and high-resolution CT scans currently miss many of the lesions eventually detected at thoracotomy and many of the lesions detected are benign. The follow-up of patients after pulmonary metastasectomy is a controversial topic because of the lack of evidence-based practice guidelines. Though it is unlikely that current follow-up recommendations will ever be tested in randomized controlled trials, meta-analyses of existing retrospective data could improve the quality of the existing literature.

Surgical salvage therapy for malignant intrathoracic metastases from nonseminomatous germ cell cancer of testicular origin: Analysis of a single-institution experience

BACKGROUND

Cisplatin-based chemotherapy followed by surgical extirpation of residual benign disease represents the usual sequence of curative therapy for metastatic nonseminomatous germ cell cancer of testicular origin. Occasionally, residual disease is malignant in the form of either a persistent nonseminomatous germ cell cancer tumor or degeneration into non-germ cell cancer. We reviewed our institution's experience with patients undergoing salvage operations to remove malignant intrathoracic metastases.

METHODS

From 1981 through 2001, 438 patients with nonseminomatous germ cell cancer had operations to remove residual intrathoracic disease after cisplatin-based chemotherapy at Indiana University Hospital. A subset of 134 patients who underwent 186 surgical procedures to remove malignant metastases is the basis of this review. Fifty-nine patients had removal of pulmonary metastases, 49 had removal of mediastinal metastases, and 26 had removal of both pulmonary and mediastinal metastases. Surgical pathology demonstrated 84 patients with persistent nonseminomatous germ cell cancer tumors, 38 with degeneration into non-germ cell cancer, and 12 with both malignant pathologic categories.

RESULTS

There were 4 (3.7%) operative deaths. The overall median survival was 5.6 years, with 55 (42.3%) patients alive and well after a mean follow-up of 5.1 years. Seventeen variables were analyzed by using Cox regression. Of these, older age, pulmonary metastases (vs mediastinal metastases), and 4 or more (vs 1) total intrathoracic metastases were significantly (P < or = .01) predictive of inferior long-term survival.

CONCLUSIONS

Salvage thoracic surgery to remove malignant metastases from nonseminomatous germ cell cancer tumors of testicular origin can result in long-term survival in select patients. We identified variables that influence survival in this subset.