Testis conserving chemotherapy in germ cell cancer: its potential to increase understanding of the biology and treatment of carcinoma-in-situ

Complete testicular remission after chemotherapy in a patient with advanced seminoma: is the testicle a real 'sanctuary'? A case report and review of the literature

Testicular cancer is relatively uncommon, but at the same time, it is the most common solid tumor in men between the ages of 20 and 34 years. Seminoma represents the most frequently encountered germ cell tumors. Because orchiectomy is usually performed before chemotherapy, little is known about the effect of systemic chemotherapy on primary testicular tumors. Furthermore, the testis has always been considered a sanctuary site, an immune-privileged site in which inadequate exposure of the tumor to chemotherapy may occur. We report the case of a young patient with advanced seminoma with a complete testicular response after four cycles of cisplatin-based chemotherapy. Then, we performed a systematic review of the literature reporting the studies published to date on the topic.

Blood testis barrier revisited-Analysis of post-chemotherapy germ cell tumor orchidectomy and retroperitoneal lymph node dissection specimens

OBJECTIVE

To assess the response of chemotherapy on the primary tumor, compare it with the response in retroperitoneal disease, and study factors associated with pathological complete response.

METHODS

We conducted a retrospective audit of all high inguinal orchidectomies (HIOs) performed after chemotherapy between 2012 and 2019 at a tertiary cancer center in India. Patient characteristics and histopathological response were extracted from electronic medical records, and predictors of testicular disease response were assessed.

RESULTS

Of the 260 retroperitoneal lymph node dissections (RPLNDs) performed in the study period, 37 HIOs (14.23%) were carried out after chemotherapy. The median age of presentation was 28 years (16-41). Histopathology was divided into a viable tumor, mature teratoma, and necrosis/scarring. Residual disease was seen in 17 RPLND (46.0%) and 18 HIO (48.6%) specimens respectively. Of these 18, three patients had a residual viable tumor in the testis, and the remaining had a mature teratoma. Clinico-radiological assessment showed an average reduction of 61% in testicular disease size following chemotherapy. On orchidectomy histopathological assessment, the median tumor size was 9, 4, and 1.5 cm in specimens with a viable tumor, mature teratoma, and necrosis/scarring, respectively.

CONCLUSIONS

A low threshold for upfront chemotherapy in patients with a high disease burden may be considered as tumors within the testis respond to chemotherapy in more than half of the patients. Discordance rates of residual cancer in RPLND and HIO specimens exist but post-chemotherapy tumor size in testis correlates with the presence of a residual viable tumor.

Histology, 12p status, and IMP3 expression separate subtypes in testicular teratomas

Introduction

Two types of testicular teratomas are distinguished by the current WHO classification. Prepubertal-type teratomas are benign, while postpubertal-type teratomas are considered malignant with metastatic potential, and are associated with germ cell neoplasia in situ. Prepubertal-type cases have been reported in the adult testis potentially causing confusion and overtreatment. Demonstration of the absence of 12p abnormalities with fluorescence in situ hybridization may facilitate diagnosis. Recently, IMP3 has emerged as a potential marker of malignancy in this context.

Aims

The aim of this study was to assess histological characteristics, IMP3 expression and the presence of 12p abnormalities of pure testicular teratomas.

Results

Thirty-seven cases were studied, 7 patients were children and 30 were adults. Six out of 7 pediatric cases showed no 12p abnormality and were IMP3 positive. Seventy-four percent and 79% of adult cases showed 12p abnormalities and IMP3 expression, respectively. Negative cases were not associated with in situ neoplasia or metastasis, they were smaller (mean, 14 vs 39 mm), showed less histological diversity (2.4 vs 4.0 types of tissues on average) compared to positive cases.

Conclusion

Our study provides further evidence that prepubertal-type (type I) teratomas may appear in adult testes, thus teratomas in adults may be either benign (type I) or malignant (type II). IMP3 expression may aid the distinction between type I and type II teratomas of the postpubertal testis even when GCNIS and 12p status cannot be assessed.

Electronic supplementary material

The online version of this article (10.1007/s00428-020-02771-2) contains supplementary material, which is available to authorized users.

Role of chemotherapy prior to orchiectomy in metastatic testicular cancer-is testis really a sanctuary site?

A germ-cell tumour (GCT) of the testis is a chemosensitive tumour with high cure rates even in advanced disease. Radical inguinal orchiectomy is the initial procedure used to diagnose it which helps to risk-stratify these patients. However, in patients with life-threatening metastases, primary chemotherapy was attempted in a few studies, followed by delayed orchiectomy. The aim of this review is to study the histopathological findings of delayed orchiectomy and the retroperitoneal lymph node dissection (RPLND) specimens, to assess difference and concordance in response rates in histological types of GCTs in pathological specimens. Overall, 352 patients received initial chemotherapy followed by orchiectomy, and 235 of them had undergone RPLND. Delayed orchiectomy specimens had viable tumour in 74 (21%) patients, scarring/necrosis in 171 patients (48.5%), and teratoma in 107 (30.3%) patients. RPLND specimens had residual disease in 36 (15.3%) patients, scarring/necrosis in 100 patients (42.5%), and teratoma in 99 patients (42.3%). Patients with seminoma who underwent delayed orchiectomy had complete disappearance of tumour in 81.3% of cases, and in non-seminomatous GCT, it was 43.4%. These results raise the question of the existence of a blood–testis barrier in patients with advanced GCT and argue against the testis as a sanctuary site.

Probability of metachronous testicular cancer in patients with biopsy-proven intratubular germ cell neoplasia depends on first-time treatment of germ cell cancer

PURPOSE

To evaluate the probability of subsequent testicular cancer (STC) in patients with intratubular germ cell neoplasia unclassified (IGCNU) treated for first-time invasive germ cell cancer.

PATIENTS AND METHODS

Sixty-one patients with germ cell testicular cancer or extragonadal germ cell cancer received follow-up from diagnosis of IGCNU to development of STC, initiation of IGCNU-definitive treatment (orchiectomy/radiotherapy), emigration, death, or end of follow-up. The probability of STC was assessed in subgroups according to chemotherapy burden.

RESULTS

The probability of STC in the nonexposed patients was significantly increased compared with those exposed to chemotherapy (P = .05; 5-year probability of 54% [95% CI, 33% to 78%] and 23% [95% CI, 11% to 45%], respectively). In the group of patients treated with one to three cycles or no chemotherapy, the probability of STC was significantly increased compared with those exposed to four or more cycles (P = .03; 5-year probability of 42% [95% CI, 27% to 62%] and 22% [95% CI, 8% to 54%], respectively). Twenty-two of 22 patients were tumor-free and alive at a median of 56 months (range, 2 to 184 months) after diagnosis of STC.

CONCLUSION

Platinum-based chemotherapy may reduce the probability of STC in patients with IGCNU, particularly in those treated with four or more cycles of chemotherapy. A watch-and-wait strategy for patients with IGCNU may be justified in selected patients with future plans for paternity.

Randomized trial of carboplatin versus radiotherapy for stage I seminoma: mature results on relapse and contralateral testis cancer rates in MRC TE19/EORTC 30982 study (ISRCTN27163214)

PURPOSE

Initial results of a randomized trial comparing carboplatin with radiotherapy (RT) as adjuvant treatment for stage I seminoma found carboplatin had a noninferior relapse-free rate (RFR) and had reduced contralateral germ cell tumors (GCTs) in the short-term. Updated results with a median follow-up of 6.5 years are now reported.

PATIENTS AND METHODS

Random assignment was between RT and one infusion of carboplatin dosed at 7 × (glomerular filtration rate + 25) on the basis of EDTA (n = 357) and 90% of this dose if determined on the basis of creatinine clearance (n = 202). The trial was powered to exclude a doubling in RFRs assuming a 96-97% 2-year RFR after radiotherapy (hazard ratio [HR], approximately 2.0).

RESULTS

Overall, 1,447 patients were randomly assigned in a 3-to-5 ratio (carboplatin, n = 573; RT, n = 904). RFRs at 5 years were 94.7% for carboplatin and 96.0% for RT (RT-C 90% CI, 0.7% to 3.5%; HR, 1.25; 90% CI, 0.83 to 1.89). One death as a result of seminoma (in RT arm) occurred. Patients receiving at least 99% of the 7 × AUC dose had a 5-year RFR of 96.1% (95% CI, 93.4% to 97.7%) compared with 92.6% (95% CI, 88.0% to 95.5%) in those who received lower doses (HR, 0.51; 95% CI, 0.24 to 1.07; P = .08). There was a clear reduction in the rate of contralateral GCTs (carboplatin, n = 2; RT, n = 15; HR, 0.22; 95% CI, 0.05 to 0.95; P = .03), and elevated pretreatment follicle-stimulating hormone (FSH) levels (> 12 IU/L) was a strong predictor (HR, 8.57; 95% CI, 1.82 to 40.38).

CONCLUSION

These updated results confirm the noninferiority of single dose carboplatin (at 7 × AUC dose) versus RT in terms of RFR and establish a statistically significant reduction in the medium term of risk of second GCT produced by this treatment.

Management of the contralateral testicle in patients with unilateral testicular cancer

Patients with a prior history of a germ cell tumor of the testicle are known to have an increased risk of development of a second germ cell tumor in the contralateral testicle. It is believed that all patients who develop a germ cell tumor of the testicle have a precursor lesion know as carcinoma in situ (CIS) or intratubular germ cell neoplasia. Approximately 50% of these patients will subsequently go on to develop a germ cell tumor in the testicle. A biopsy of the contralateral testicle in a patient with a previous history of a germ cell tumor of the testicle has been advocated by some, while others recommend a biopsy only in patients with other risk factors as well. The arguments for biopsy are that intervention may be used to prevent the development of a second germ cell tumor when CIS is detected. In this review we present the arguments for and against a biopsy of the contralateral testicle, review the techniques of biopsy as well as its complications, and discuss the interventions employed to prevent CIS from progressing.

Radiotherapy versus single-dose carboplatin in adjuvant treatment of stage I seminoma: a randomised trial

BACKGROUND

Adjuvant radiotherapy is effective treatment for stage I seminoma, but is associated with a risk of late non-germ-cell cancer and cardiovascular events. After good results in initial studies with one injection of carboplatin, we undertook a large randomised trial to compare the approaches of radiotherapy with chemotherapy in seminoma treatment.

METHODS

Between 1996 and 2001, 1477 patients from 70 hospitals in 14 countries were randomly assigned to receive radiotherapy (para-aortic strip or dog-leg field; n=904) or one injection of carboplatin (n=573; dose based on the formula 7x[glomerular filtration rate+25] mg), at two trial centres in the UK and Belgium. The primary outcome measure was the relapse-free rate, with the trial powered to exclude absolute differences in 2-year rates of more than 3%. Analysis was by intention to treat and per protocol. This trial has been assigned the International Standard Randomised Controlled Trial Number ISRCTN27163214.

FINDINGS

885 and 560 patients received radiotherapy and carboplatin, respectively. With a median follow-up of 4 years (IQR 3.0-4.9), relapse-free survival rates for radiotherapy and carboplatin were similar (96.7% [95% CI 95.3-97.7] vs 97.7% [96.0-98.6] at 2 years; 95.9% [94.4-97.1] vs 94.8% [92.5-96.4] at 3 years, respectively; hazard ratio 1.28 [90% CI 0.85-1.93], p=0.32). At 2 years' follow-up, the absolute differences in relapse-free rates (radiotherapy-chemotherapy) were -1.0% (90% CI -2.5 to 0.5) by direct comparison of proportions, and 0.9% (-0.5 to 3.0) by a hazard-ratio-based approach. Patients given carboplatin were less lethargic and less likely to take time off work than those given radiotherapy. New, second primary testicular germ-cell tumours were reported in ten patients allocated irradiation (all after para-aortic strip field) and two allocated carboplatin (5-year event rate 1.96% [95% CI 1.0-3.8] vs 0.54% [0.1-2.1], p=0.04). One seminoma-related death occurred after radiotherapy and none after carboplatin.

INTERPRETATION

This trial has shown the non-inferiority of carboplatin to radiotherapy in the treatment of stage I seminoma. Although the absence of disease-related deaths and preliminary data indicating fewer second primary testicular germ-cell tumours favour carboplatin use, these findings need to be confirmed beyond 4 years' follow-up.

Hypermethylation of the 5' CpG island of the gene encoding the serine protease Testisin promotes its loss in testicular tumorigenesis

The Testisin gene (PRSS21) encodes a glycosylphosphatidylinositol (GPI)-linked serine protease that exhibits testis tissue-specific expression. Loss of Testisin has been implicated in testicular tumorigenesis, but its role in testis biology and tumorigenesis is not known. Here we have investigated the role of CpG methylation in Testisin gene inactivation and tested the hypothesis that Testisin may act as a tumour suppressor for testicular tumorigenesis. Using sequence analysis of bisulphite-treated genomic DNA, we find a strong relationship between hypermethylation of a 385 bp 5′ CpG rich island of the Testisin gene, and silencing of the Testisin gene in a range of human tumour cell lines and in 100% (eight/eight) of testicular germ cell tumours. We show that treatment of Testisin-negative cell lines with demethylating agents and/or a histone deacetylase inhibitor results in reactivation of Testisin gene expression, implicating hypermethylation in Testisin gene silencing. Stable expression of Testisin in the Testisin-negative Tera-2 testicular cancer line suppressed tumorigenicity as revealed by inhibition of both anchorage-dependent cell growth and tumour formation in an SCID mouse model of testicular tumorigenesis. Together, these data show that loss of Testisin is caused, at least in part, by DNA hypermethylation and histone deacetylation, and suggest a tumour suppressor role for Testisin in testicular tumorigenesis.

Current views on the pathogenesis of testicular germ cell tumours and perspectives for future research: highlights of the 5th Copenhagen Workshop on Carcinoma in situ and Cancer of the Testis

This review article highlights the most important contributions presented at the 5th Copenhagen Workshop on Carcinoma in situ and Cancer of the Testis, which was held in Denmark, August 29-31, 2002. The major themes that emerged at the meeting are critically discussed and perspectives for future research in this field are presented.