Do all germ cell tumor patients with residual masses in multiple sites require postchemotherapy resections?

A New Model to Predict Benign Histology in Residual Retroperitoneal Masses After Chemotherapy in Nonseminoma

BACKGROUND

Postchemotherapy retroperitoneal lymph node dissection (pcRPLND) is indicated in testicular cancer patients with normalised or plateaued serum tumour markers and residual retroperitoneal lesions >1cm. Challenges remain in predicting postchemotherapy residual mass (pcRM) histology, which may lead to unnecessary surgery.

OBJECTIVE

To develop an accurate model to predict pcRM histology in patients with nonseminomatous germ cell tumours (NSGCTs).

DESIGN, SETTING, AND PARTICIPANTS

A retrospective review of 335 patients undergoing pcRPLND for metastatic NSGCTs to develop a model to predict benign histology in retroperitoneal pcRM. Our model was compared with others and externally validated.

INTERVENTION

Chemotherapy and pcRPLND.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable logistic regression to evaluate the presence of benign histology, and fractional polynomials to allow for a nonlinear association between continuous variables and the outcome. The final Princess Margaret model (PMM) was selected based on the number of variables used, reliability, and discriminative capacity to predict benign pcRM.

RESULTS AND LIMITATIONS

PMM included the presence of teratoma in the orchiectomy, prechemotherapy α-fetoprotein, prechemotherapy mass size, and change in mass size during chemotherapy. Model specificity was 99.3%. Compared with Vergouwe et al's model, PMM had significantly better accuracy (C statistic 0.843 vs 0.783). PMM appropriately identified a larger number of patients for whom pcRPLND can safely be avoided (13.9% vs 0%). Validated in external cohorts, the model retained high discrimination (C statistic 0.88 and 0.80). Larger and prospective studies are needed to further validate this model.

CONCLUSIONS

Our clinical model, externally validated, showed improved discriminative ability in predicting pcRM histology when compared with other models. The higher accuracy and reduced number of variables make this a novel and appealing model to use for patient counselling and treatment strategies.

PATIENT SUMMARY

Princess Margaret model accurately predicted postchemotherapy benign histology. These results might have clinical impact by avoiding unnecessary retroperitoneal lymph node dissection and consequently changing the paradigm of advanced testicular cancer treatment.

Salvage Therapy for Patients With Germ Cell Tumor

The introduction of cisplatin combination chemotherapy, 40 years ago, transformed metastatic testicular germ cell tumors from an almost uniformly fatal disease into a model for a curable neoplasm. Before the era of platinum combination chemotherapy, the 5-year survival rate among men with metastatic testicular germ cell tumors was 5% to 10%. Currently, the 5-year survival rate is 80% for patients with metastatic disease and 95% overall. Despite the substantial advances in the treatment of germ cell tumors, 20% to 30% of patients will relapse after first-line chemotherapy and will require additional salvage therapies. Standard-dose or high-dose chemotherapy can cure ≤ 50% of these patients. Relapses after high-dose chemotherapy generally carry a poor prognosis; however, cure is still possible in a small percentage of patients by using further salvage chemotherapy or salvage surgery.

Handling and Reporting of Biopsy and Surgical Specimens of Testicular Cancer

This paper is the result of a meeting of the European Association of Pathologists, Uropathology Division in Florence 2003. The aims of this meeting were to establish: guidelines for specimen handling by urologists and minimum requirements for data accompanying testicular specimens submitted to pathologists; a consensus on techniques for processing specimens by pathologists; the essential information required from pathology reports; areas where our standard practice is traditional rather than evidence based and where further studies are required. The general aims of histopathology are to give or confirm a diagnosis; assess established prognostic markers; identify changes associated with treatment; provide information for audit (i.e. imaging, urology and pathology) and maintain a permanent record (slides/blocks).

Role of P53 and MDM2 in treatment response of human germ cell tumors

PURPOSE

Testicular germ cell tumors (TGCTs) of adolescents and adults are very sensitive to systemic treatment. The exquisite chemosensitivity of these cancers has been attributed to a high level of wild-type P53.

MATERIALS AND METHODS

To clarify the role of P53 in treatment sensitivity and resistance of TGCTs, we performed immunohistochemistry and Western blotting analysis on a series of 39 fresh-frozen primary TGCTs before therapy (unselected series). In a series of formalin-fixed paraffin-embedded TGCTs of patients with fully documented clinical course, including treatment-sensitive (n = 17) and -resistant (n = 18) tumors, P53 status was assessed by immunohistochemistry and mutation analysis. In addition, the involvement of MDM2, a P53 antagonist, was investigated by immunohistochemistry, reverse transcriptase polymerase chain reaction, and in situ hybridization.

RESULTS

Immunohistochemistry demonstrated absence of staining for P53 in 36%, 41%, and 17% of the unselected, responding, and nonresponding TGCTs, respectively. Of the positive TGCTs, most tumors, ie, 49%, 41%, and 33%, showed 1% to 10% positive nuclei. This overall low level of P53 was confirmed by Western blotting. Mutation analysis revealed only one silent P53 mutation in one of the responding patients. All embryonal carcinomas were homogeneously positive for MDM2, encoded by the full length mRNA, while a heterogeneous pattern was found for the other histologic components. Amplification of MDM2 was detected in one out of 12 embryonal carcinomas.

CONCLUSION

Although our results are in line with previous findings of the presence of wild-type P53 in TGCTs, they show that a high level of P53 does not relate directly to treatment sensitivity of these tumors, and inactivation of P53 is not a common event in the development of cisplatin resistance.

Viable Malignant Cells After Primary Chemotherapy for Disseminated Nonseminomatous Germ Cell Tumors: Prognostic Factors and Role of Postsurgery Chemotherapy—Results From an International Study Group

PURPOSE: To assess the value of postsurgery chemotherapy in patients with disseminated nonseminomatous germ-cell tumors (NSGCTs) and viable residual disease after first-line cisplatin-based chemotherapy.

PATIENTS AND METHODS: The outcome of 238 patients was reviewed. Tumor markers had normalized in all patients before resection. A multivariate analysis of survival was performed on 146 patients.

RESULTS: The 5-year progression-free survival (PFS) rate was 64% and the 5-year overall survival (OS) rate was 73%. Three factors were independently associated with both PFS and OS: complete resection (P < .001), < 10% of viable malignant cells (P = .001), and a good International Germ Cell Consensus Classification (IGCCC) group (P = .01). Patients were assigned to one of three risk groups: those with no risk factors (favorable group), those with one risk factor (intermediate group), and those with two or three risk factors (poor-risk group). The 5-year OS rate was 100%, 83%, and 51%, respectively (P < .001). The 5-year PFS rate was 69% (95% confidence interval [CI], 62% to 76%) and 52% (95% CI, 40% to 64%) in postoperative chemotherapy recipients and nonrecipients, respectively (P < .001). No significant difference was detected in 5-year OS rates. After adjustment on the three prognostic factors, postoperative chemotherapy was associated with a significantly better PFS (P < .001) but not with better OS. Patients in the favorable risk group had a 100% 5-year OS, with or without postoperative chemotherapy. Postoperative chemotherapy appeared beneficial in both PFS (P < .001) and OS (P = .02) in the intermediate-risk group but was not statistically beneficial in the poor-risk group.

CONCLUSION: A complete resection may be more critical than recourse to postoperative chemotherapy in the setting of postchemotherapy viable malignant NSGCT. Immediate postoperative chemotherapy or surveillance alone with chemotherapy at relapse may be reasonable options depending on the completeness of resection, IGCCC group, and percent of viable cells. Validation is necessary.

The role of the histopathologist in the management of testicular germ cell tumour in adults

In the last 20--30 years the availability of effective chemotherapy and more accurate clinical staging has greatly improved the prognosis for patients with testicular germ cell tumours. Initially, such treatment appeared to diminish the role of histopathology to the distinction between seminoma and nonseminomatous germ cell tumour (NSGCT) in the primary specimen. However, histopathology has evolved as a prognostic tool indicating the risk of relapse in various defined clinical contexts thereby facilitating therapeutic decisions. The clinical emphasis has been on quality of life and reduction of therapy both in terms of the number of patients treated and the number of chemotherapy courses given to each patient. The treatment of adult testicular germ cell tumours may differ between countries but protocols are established. Therefore it is appropriate to discuss the role of histopathology during this era of relative therapeutic stability.

Thoracotomy for postchemotherapy resection of pulmonary residual tumor mass in patients with nonseminomatous testicular germ cell tumors: aggressive surgical resection is justified

In patients with disseminated nonseminomatous testicular germ cell tumors (NSTGCT), a retroperitoneal residual tumor mass (RRTM) and/or a pulmonary residual tumor mass (PRTM) are often present after successful treatment with cisplatin-based polychemotherapy. Results and complications of postchemotherapy resection of PRTM were studied and survival was calculated. In the period 1979 to 1996, 31 patients with a median age of 28 years (range, 17 to 44 years) underwent 32 thoracotomies for the resection of a PRTM. A solitary lesion was encountered nine times (28.1%) and multiple lesions were encountered 23 times (71.9%). The median size was 15 mm (range, 2 to 60 mm). There were only three major postoperative complications (9.6%): prolonged ventilation, pneumothorax, and pneumonia. In 16 patients (51.6%), the resected PRTM showed mature teratoma, while in four patients (12.9%) it showed viable cancer. In 11 patients only necrosis and/or fibrosis were found (35.5%). Resection of an RRTM had been performed prior to thoracotomy in 20 patients. There was dissimilarity between the histologic features of the resected RRTM and PRTM in 10 of the 20 patients (50%). During a median follow-up of 80 months (range, 2.5 to 203 months), five patients died from metastatic disease (16.1%). The 5-year survival rate was 86.8% and the 10-year survival rate was 82.2%. Owing to the dissimilarity between the histologic features of the postchemotherapy resected RRTM and PRTM in 50% of the patients, all sites of pulmonary residual disease must be resected in patients with disseminated NSTGCT, irrespective of the histologic features of previously resected retroperitoneal residual disease. This approach offers minimal morbidity and a high 10-year survival rate.