Surgical Management of Patients with Advanced Germ Cell Tumors Following Salvage Chemotherapy: Memorial Sloan Kettering Cancer Center (MSKCC) Experience

The Use of Salvage Chemotherapy for Patients with Relapsed Testicular Germ Cell Tumor (GCT) in Canada: A National Survey

BACKGROUND

Although metastatic germ cell tumor (GCT) is highly curable with initial cisplatin-based chemotherapy (CT), 20-30% of patients relapse. Salvage CT options include conventional (CDCT) and high dose chemotherapy (HDCT), however definitive comparative data remain lacking. We aimed to characterize the contemporary practice patterns of salvage CT across Canada.

METHODS

We conducted a 30-question online survey for Canadian medical and hematological oncologists with experience in treating GCT, assessing treatment availability, patient selection, and management strategies used for relapsed GCT patients.

RESULTS

There were 30 respondents from 18 cancer centers across eight provinces. The most common CDCT regimens used were TIP (64%) and VIP (25%). HDCT was available in 13 centers (70%). The HDCT regimen used included carboplatin and etoposide for two cycles (76% in 7 centers), three cycles (6% in 2 centers), and the TICE protocol (11%, in 2 centers). "Bridging" CDCT was used by 65% of respondents. Post-HDCT treatments considered include surgical resection for residual disease (87.5%), maintenance etoposide (6.3%), and surveillance only (6.3%).

CONCLUSIONS

HDCT is the most commonly used GCT salvage strategy in Canada. Significant differences exist in the treatment availability, selection, and delivery of HDCT, highlighting the need for standardization of care for patients with relapsed testicular GCT.

High-dose chemotherapy for relapsed testicular germ cell tumours

Relapsed testicular germ cell tumours (GCTs) might be cured with salvage chemotherapy. Accepted salvage treatment is conventional-dose chemotherapy (CDCT) or high-dose chemotherapy (HDCT). HDCT with peripheral blood stem cell transplant might produce a higher number of durable responses than CDCT. We discuss studies reporting on outcomes of salvage HDCT in relapsed GCTs. The most reproducible results were achieved with HDCT with two cycles of etoposide and carboplatin or three cycles of the paclitaxel, ifosfamide, carboplatin and etoposide regime. Using these two regimens, sustained cure rates of 50-66% were reported in phase I, phase II and retrospective studies published in the past two decades. Cure rates in patients with cisplatin-resistant disease are between 30% and 45%. Two phase III randomized studies were conducted with certain limitations and were unsuccessful in showing a survival benefit of HDCT. Thus, salvage treatment remains a controversial topic. Salvage HDCT with peripheral blood stem cell transplant and CDCT are two recommended treatment options for relapsed GCTs. Consistently reported cure rates from phase I, phase II and large retrospective studies support the use of HDCT in the hands of an experienced team of oncologists.

Thoracic Metastasectomy in Germ Cell Tumor Patients Treated With First-line Versus Salvage Therapy

BACKGROUND

Outcomes after thoracic metastasectomy in patients with testicular germ cell tumors (GCTs) who received first-line chemotherapy alone versus salvage chemotherapy remain unexplored.

METHODS

We conducted a retrospective review of patients who underwent thoracic metastasectomy for residual GCT between 1997 and 2019 at a single tertiary center. Factors associated with progression-free survival (PFS) and overall survival (OS) were assessed using multivariable Cox regression.

RESULTS

Of 251 patients, 191 received only first-line chemotherapy (76%) and 60 received salvage chemotherapy (24%). Median follow-up was 3.45 years (interquartile range, 1-7.93 years). Among first-line patients without teratoma in the primary tumor, with necrosis in the retroperitoneal nodes and normalized or decreasing serum tumor markers, 17 of 20 had intrathoracic necrosis (85%). Among first-line and salvage patients, respectively, 5-year OS was 93% (95% confidence interval [CI], 89%-98%) versus 63% (95% CI, 51%-78%; P < .001), and 5-year PFS was 69% (95% CI, 62%-77%) versus 40% (95% CI, 29%-56%; P < .001). On multivariable analysis, multiple lung lesions (hazard ratio [HR] = 3.01; 95% CI, 1.50-6.05; P = .002) and brain metastasis (HR = 4.51; 95% CI, 2.34-8.73; P < .001) at diagnosis, salvage chemotherapy (HR = 1.85; 95% CI, 1.10-3.13; P = .021), teratoma (HR = 2.68; 95% CI, 1.50-4.78; P = .001), and viable malignancy (HR = 4.34; 95% CI, 2.44-7.71; P < .001) were associated with worse PFS.

CONCLUSIONS

Although GCT patients treated with salvage chemotherapy followed by thoracic metastasectomy have more aggressive disease and poorer PFS, they can achieve encouraging OS. Our findings highlight the integral role of aggressive thoracic metastasectomy in the treatment of GCT patients with residual thoracic disease after first line-only or salvage chemotherapy.

Surgical treatment of metastatic germ cell cancer

Among young men between the ages of 15 and 40 years, germ cell cancer is the most common solid tumor [1]. The worldwide incidence of germ cell cancer is 70 000 cases. Compared to all solid tumors of men, germ cell cancer accounts for 1% of all male tumors. Nevertheless, the mortality of this rare tumor entity is about 13% since 9507 patients died worldwide of germ cell cancer. The improvement in survival of germ cell cancer patients is due to a multimodal treatment of germ cell cancer including cisplatin-based chemotherapy and surgery leading to higher cure-rates even in advanced stages [1], whereas the increasing incidence of germ cell cancers cannot be thoroughly explained. In this article we review the current indications for surgery in metastatic germ cell cancers, highlight the strength and weaknesses of techniques and indications and raise the question how to improve surgical treatment in metastatic germ cell cancer.