Radiotherapy of testicular intraepithelial neoplasia (TIN): a novel treatment regimen for a rare disease

Testicular Dysfunction in Male Childhood Cancer Survivors Treated With Radiation Therapy: A PENTEC Comprehensive Review

PURPOSE

The male reproductive task force of the Pediatric Normal Tissue Effects in the Clinic (PENTEC) initiative performed a comprehensive review that included a meta-analysis of publications reporting radiation dose-volume effects for risk of impaired fertility and hormonal function after radiation therapy for pediatric malignancies.

METHODS AND MATERIALS

The PENTEC task force conducted a comprehensive literature search to identify published data evaluating the effect of testicular radiation dose on reproductive complications in male childhood cancer survivors. Thirty-one studies were analyzed, of which 4 had testicular dose data to generate descriptive scatter plots. Two cohorts were identified. Cohort 1 consisted of pediatric and young adult patients with cancer who received scatter radiation therapy to the testes. Cohort 2 consisted of pediatric and young adult patients with cancer who received direct testicular radiation therapy as part of their cancer therapy. Descriptive scatter plots were used to delineate the relationship between the effect of mean testicular dose on sperm count reduction, testosterone, follicle stimulating hormone (FSH), and luteinizing hormone (LH) levels.

RESULTS

Descriptive scatter plots demonstrated a 44% to 80% risk of oligospermia when the mean testicular dose was <1 Gy, but this was recovered by >12 months in 75% to 100% of patients. At doses >1 Gy, the rate of oligospermia increased to >90% at 12 months. Testosterone levels were generally not affected when the mean testicular dose was <0.2 Gy but were abnormal in up to 25% of patients receiving between 0.2 and 12 Gy. Doses between 12 and 19 Gy may be associated with abnormal testosterone in 40% of patients, whereas doses >20 Gy to the testes were associated with a steep increase in abnormal testosterone in at least 68% of patients. FSH levels were unaffected by a mean testicular dose <0.2 Gy, whereas at doses >0.5 Gy, the risk was between 40% and 100%. LH levels were affected at doses >0.5 Gy in 33% to 75% of patients between 10 and 24 months after radiation. Although dose modeling could not be performed in cohort 2, the risk of reproductive toxicities was escalated with doses >10 Gy.

CONCLUSIONS

This PENTEC comprehensive review demonstrates important relationships between scatter or direct radiation dose on male reproductive endpoints including semen analysis and levels of FSH, LH, and testosterone.

Testicular germ cell tumour arising 15 years after radiotherapy with 18 Gy for germ cell neoplasia in situ

PURPOSE

Germ cell neoplasia in situ (GCNis), the precursor of adult testicular germ cell tumours (GCTs), is found in 5-6% of contralateral testicles in patients with testicular GCT and in the tumour-surrounding tissue of > 90% of testes undergoing testis-sparing surgery (TSS) for GCT. Local radiotherapy to the testis with 18-20 Gy eradicates GCNis while preserving Leydig cells. The frequency of treatment failures is so far unknown.

METHODS

A 22-year-old patient with right-sided seminoma clinical stage I and contralateral GCNis received radiotherapy with 18 Gy to his left testicle. Fifteen years later he underwent orchiectomy of the irradiated testis for seminoma with adjacent GCNis. The patient is well 1 year postoperatively while on testosterone-replacement therapy. The literature was searched for further cases with GCTs arising despite local radiotherapy.

RESULTS

Six failures of radiotherapy have been reported previously. An estimated total number of 200 and 100 radiotherapeutic regimens with 18-20 Gy applied to cases with contralateral GCNis and with TSS, respectively, are documented in the literature.

CONCLUSION

Cumulative experience suggests that radiotherapy with 18-20 Gy to the testis may fail with an estimated frequency of around 1%. Reasons for failure are elusive. A primary radioresistant subfraction of GCNis is hypothesized as well as technical failures regarding application of the radiotherapeutic dose volume in small and mobile testes. Caregivers of patients with TSS and contralateral GCNis should be aware of local relapses occurring after intervals of > 10 years.

Oncological and functional outcomes after testis-sparing surgery in patients with germ cell tumors: a systematic review of 285 cases

INTRODUCTION AND OBJECTIVES

In several urogenital cancers, organ-preserving surgery represents the preferred treatment approach, but in patients with testicular germ cell tumors (tGCTs), radical orchiectomy represents the standard of care. This study aimed to summarize published case series assessing oncological and functional outcomes after testis-sparing surgery (TSS) in patients with tGCTs.

MATERIALS AND METHODS

A systematic literature review and individual patient data meta-analysis were conducted of published cases with tGCT treated with TSS.

RESULTS

Of 2,333 reports, we included 32 reports providing data on 285 patients, including 306 testicles treated with TSS. Adjacent germ cell neoplasia in situ (GCNIS) was described in 43%. Hypogonadism and infertility after TSS were diagnosed in 27% and 18%. In patients undergoing adjuvant testicular radiotherapy, hypogonadism was diagnosed in 40%. Patients treated with adjuvant testicular radiotherapy after TSS exhibited a significantly lower incidence of local recurrence (2% vs. 50%, p < 0.001). Distant metastases after TSS were observed in 2%.

CONCLUSION

The current data questions the benefits of TSS in tGCT patients. If at all, TSS should only be offered to well-informed patients with a singular testicle, excellent compliance, a singular tumor less than 2 cm located at the lower pole of the testicle, and normal preoperative endocrine function. Unless patients plan to father a child within a short time frame, adjuvant testicular radiotherapy should be recommended after TSS. Radical orchiectomy remains the standard of care, but future studies may support the use of TSS in selected men.

Treatment of testicular intraepithelial neoplasia (intratubular germ cell neoplasia unspecified) with local radiotherapy or with platinum-based chemotherapy: a survey of the German Testicular Cancer Study Group

BACKGROUND

The treatment of testicular intraepithelial neoplasia (TIN), the progenitor of testicular germ cell tumours (GCTs), is based on little data.

PATIENTS AND METHODS

Two hundred and twenty-eight GCT patients with contralateral TIN were retrospectively enrolled. Ten had surveillance, 122 radiotherapy to testis with 18-20 Gy, 30 cisplatin-based chemotherapy (two cycles), 51 chemotherapy (three cycles), and 15 carboplatin. The study end point was a malignant event (ME), defined as detection of TIN upon control biopsy or occurrence of a second GCT. The Secondary end point was hypogonadism during follow-up.

RESULTS

Numbers, proportions of ME, and median event-free survival (EFS) times were: radiotherapy N = 3, 2.5%, 11.08 years; chemotherapy (two cycles) N = 15, 50%, 3.0 years; chemotherapy (three cycles) N = 12, 23.5%, 9.83 years; carboplatin N = 10, 66%, 0.9 years; surveillance N = 5, 50%, 7.08 years. EFS is significantly different among the groups. Hypogonadism rates were in radiotherapy patients 30.8%, chemotherapy (two cycles) 13%, chemotherapy (three cycles) 17.8%, carboplatin 40%, surveillance 40%.

CONCLUSIONS

Local radiotherapy is highly efficacious in curing TIN. Chemotherapy is significantly less effective and the cure rates are dose-dependent. Though hypogonadism occurs in one-third of patients, radiotherapy with 20 Gy remains the standard management of TIN.

Scrotal irradiation in primary testicular lymphoma: review of the literature and in silico planning comparative study

We examined adjuvant irradiation of the scrotum in primary testicular lymphoma (PTL) by means of a literature review in MEDLINE, a telephone survey among Dutch institutes, and an in silico planning comparative study on scrotal irradiation in PTL. We did not find any uniform adjuvant irradiation technique assuring a safe planning target volume (PTV) coverage in published reports, and the definition of the clinical target volume is unclear. Histopathologic studies of PTL show a high invasion rate of the tunica albuginea, the epididymis, and the spermatic cord. In retrospective studies, a prescribed dose of at least 30 Gy involving the scrotum is associated with best survival. The majority of Dutch institutes irradiate the whole scrotum without using a planning computed tomography scan, with a single electron beam and a total dose of 30 Gy. The in silico planning comparative study showed that all evaluated approaches met a D(95%) scrotal dose of at least 85% of the prescription dose, without exceeding the dose limits of critical organs. Photon irradiation with 2 oblique beams using wedges resulted in the best PTV coverage, with a mean value of 95% of the prescribed dose, with lowest maximum dose. Adjuvant photon or electron irradiation of the whole scrotum including the contralateral testicle with a minimum dose of 30 Gy is recommended in PTL. Computed tomography-based radiation therapy treatment planning with proper patient positioning and position verification guarantees optimal dose coverage.

Intratubular germ cell neoplasms of the testis and bilateral testicular tumors: clinical significance and management options

Objectives:

Intratubular germ cell neoplasia (ITGCN) is the precursor lesion for invasive testicular germ cell tumors (TGCTs) of adolescents and young adults. The rising incidence of these tumors has prompted a rigorous investigation of the etiology, diagnosis and management of ITGCN. Bilateral testicular cancer is closely linked with ITGCN, as patients with unilateral testicular cancer are at the highest risk for a future malignancy in the contralateral testicle.

Methods:

A literature review directed at ITGCN and bilateral testis cancer was performed using the Medline/PubMed database. Our review focused on the pathogenesis, risk factors, diagnosis and treatment regimens utilized.

Results:

Major advances have been made in the understanding of ITGCN over the past 30 years. There is evidence that TGCTs arise from ITGCN, ITGCN is closely related to fetal gonocytes, and that events in pre- and perinatal period may result in abnormal persistence of fetal gonocytes leading to ITGCN and subsequent TGCT. Controversy exists regarding the need to biopsy men at increased risk of TGCT, as well as the best approach to managing patients with known ITGCN. Bilateral testicular cancer has excellent outcomes in the current era of platinum-based chemotherapy.

Conclusion:

The optimal management of patients at risk for ITGCN and future TGCT is still a matter of debate. Individualization of management, including biopsy and treatment, should be based on risk factors for TGCT, compliance with potential surveillance, and patient preferences particularly with regard to fertility.

Transcutaneous high-intensity focused ultrasonography can cure testicular cancer in solitary testis

OBJECTIVES

To report the long-term results in 7 patients (including the 5-year results in 3 patients) after high-intensity focused ultrasonography (HIFU) combined with irradiation to treat testicular tumors in a solitary testis.

METHODS

Transcutaneous HIFU ablation of testicular tumors is based on a technique using a piezoceramic transducer operating at 4.0 MHz with a site intensity of 1600 to 2000 W/cm2. In a Phase II trial, 7 patients with the typical sonographic pattern of a tumor in a solitary testis were treated with transcutaneous HIFU, as a minimally invasive organ-preserving approach, followed 6 weeks later by prophylactic testicular irradiation (range 18 to 20 Gy). The aim was to ablate the entire cancer in a single therapeutic HIFU session. In all 7 patients, the contralateral testis had previously been removed because of testicular cancer.

RESULTS

One patient received two cycles of chemotherapy for a single suspicious retroperitoneal lymph node diagnosed 6 months after HIFU. The other 6 protocol-treated patients remained tumor free at a mean follow-up of 42 months (range 3 to 93). One patient, who had refused postoperative irradiation, developed a recurrent tumor within 6 months. No patient showed any signs of clinical hypogonadism, and the International Index of Erectile Function score was normal for all patients. No androgen substitution was necessary. The only adverse effect noted was a small thermal lesion of the scrotum in 1 patient.

CONCLUSIONS

Despite the lack of tumor histologic examination, transcutaneous HIFU followed by irradiation permits a minimally invasive, organ-preserving, curative treatment for tumors in a solitary testis.

Rat testis as a radiobiological in vivo model for radionuclides

The radiobiological effect of intracellularly localised radionuclides emitting low energy electrons (Auger electrons) has received much attention. Most in vivo studies reported have been performed in the mouse testis. We have investigated the rat testis as an in vivo radiobiological model, with sperm-head survival, testis weight loss and also alteration in the blood plasma hormone levels of FSH and LH as radiobiological endpoints. Validation of the rat testis model was evaluated by using mean absorbed doses of up to 10 Gy from intratesticularly (i.t.) injected (111)In oxine or local X-ray irradiation. Biokinetics of the i.t. injected radionuclide was analysed by scintillation camera imaging and used in the absorbed dose estimation. By the analysis of the autoradiographs, the activity distribution was revealed. Cell fractionation showed (111)In to be mainly associated with the cell nuclei. External irradiations were monitored by thermoluminescence dosimeters. The sperm-head survival was the most sensitive radiobiological parameter correlated to the mean absorbed dose, with a D(37) of 2.3 Gy for (111)In oxine and 1.3 Gy for X rays. The levels of plasma pituitary gonadal hormones FSH and LH were elevated for absorbed doses >7.7 Gy. This investigation shows that the radiobiological model based on the rat testis has several advantages compared with the previously commonly used mouse testis model. The model is appropriate for further investigations of basic phenomena such as radiation geometry, intracellular kinetics and heterogeneity, crucial for an understanding of the biological effect of low-energy electrons.

CONSERVATIVE MANAGEMENT OF SMALL TESTICULAR TUMORS RELATIVE TO CARCINOMA IN SITU PREVALENCE

PURPOSE

We evaluated the prevalence of carcinoma in situ (CIS) in orchiectomy specimens performed for germ cell tumors smaller than 40 mm in diameter to propose an appropriate conservative approach to bilateral tumors or tumor of a solitary testis.

MATERIALS AND METHODS

Of 127 patients treated with orchiectomy between 1990 and 2002, 41 who presented with a tumor of less than 40 mm in diameter were selected for histological analysis of testicular parenchyma. The morphological items assessed were CIS, spermatogenesis and Leydig cell hyperplasia.

RESULTS

CIS was observed in 39 of the 41 patients (95%). CIS was evenly distributed throughout the testicular parenchyma (ie around and beyond the tumor) in all 39 cases. Spermatogenesis was observed in 12 of 41 specimens (29%), spermatogenesis without spermatozoa was noted in 14 (34%) and absent germ cells were found in 15 (37%). Leydig cell hyperplasia was observed in 24 cases (58%).

CONCLUSIONS

Histological analysis of whole orchiectomy specimens showed that CIS is almost always present in testicular parenchyma adjacent to germ cell tumor. In bilateral testis cancer or cancer occurring in a solitary testis tumorectomy plus radiotherapy appears to be the appropriate treatment in patients with a small tumor and no other risk factors. In patients who wish to father a child and have preserved spermatogenesis the natural history of CIS allows the postponement of testicular radiotherapy after orchiectomy, giving the double advantage of preserving testicular endocrine function and maintaining the possibility of natural fatherhood.

[Diagnosis and primary treatment of testicular tumor]

In cases of suspected testicular germ cell cancer, the first diagnostic steps include scrotal sonography, ultrasound of the retroperitoneum and abdomen, determination of serum tumor markers (AFP, betaHCG, LDH), and inguinal orchiectomy with contralateral scrotal testicular biopsy. Histology of the orchiectomized testis is essential for the patient's further treatment options. For synchronous or metachronous bilateral testis cancer or germ cell cancer in a single testis, organ-sparing surgery with resection of the (small) tumor (<2 cm) is possible. After these initial steps, further diagnostic procedures include computed tomography of the abdomen/pelvis and lung. In cases of hematogeneous spread of the disease, bone scan and CT or MR of the brain are performed additionally. The determination of serum tumor markers after orchiectomy is mandatory. Treatment of testicular cancer is based on exact knowledge of the histological type and stage of the disease. In metastatic testis cancer treatment modalities are defined according to the prognosis of the tumor (defined by the IGCCCG). In cases of testicular intraepithelial neoplasia (TIN) of the contralateral testis or in residual testicular tissue after tumor enucleation, three available treatment options can be discussed with the patient: orchiectomy, radiotherapy, or surveillance. The decision depends on the individual situation of the patient. Radiotherapy with 20 Gy is accepted as standard treatment. In general, treatment of testis cancer is associated with gonadal toxicity. Therefore, prior to further treatment, aspects of family planning, wish for children, and the option to cryopreserve semen (in cases of azoospermia cryopreservation of testicular tissue) have to be discussed.

Bilateral germ-cell tumours: 22-year experience at the Institut Gustave Roussy

The aim of this study was to describe the incidence, clinical and histological characteristics, treatment and long-term follow-up of bilateral germ-cell tumours (BGCT) of the testis in order to determine in what respects they differ significantly from unilateral germ-cell tumours. In all, 31 patients with BGCT had metachronous tumours and 14 had synchronous tumours. Among the metachronous tumours, 61% occurred more than 5 years after the first tumour. The overall incidence of BGCT in patients with testicular germ-cell tumours (TGCT) was 1.9%. The incidence was 3.2% in patients presenting with a seminoma and 1.4 % in patients presenting with a nonseminomatous germ-cell tumour (NSGCT). Patients under 30 years of age at the time of the initial diagnosis had a higher incidence of bilateral tumours compared with older men. The outcome of BGCT was excellent. A high association was found between BGCT, sterility and suspected genetic risk factors for TGCT. These results argue against a systematic contralateral biopsy at diagnosis of first TGCT in all patients, but emphasise the importance of patient education and of the need to better identify patients at risk for a second TGCT. Therapeutic indications for synchronous BGCT, including conservative treatment, need to be better defined.

Radiotherapy with 16 Gy may fail to eradicate testicular intraepithelial neoplasia: preliminary communication of a dose-reduction trial of the German Testicular Cancer Study Group

Low-dose radiotherapy to the testis is effective in eradicating testicular intraepithelial neoplasia (TIN, carcinoma in situ of the testis) at the risk of androgenic deficiency. The present trial was designed to define the lowest dose effective to control TIN assuming a dose-response relation of radiation-induced endocrinological damage. Patients with TIN in a solitary testicle or with bilateral TIN were treated with 18 Gy (14 patients) and 16 Gy (26 patients) (5 x 2 Gy per week). Biopsies to ascertain clearance of TIN were performed after 6 and 24 months. The median time of follow-up is 20.5 months. There were three adverse events. In one patient, relapse of TIN along with microinvasive seminoma was observed 2 years after 16 Gy irradiation. In two other patients, persistent spermatogonia were observed with the 16 and 18 Gy regimen after 6 and 24 months, respectively. All other post-treatment biopsies showed the Sertoli cell-only pattern. These results confirm that TIN is a radiosensitive lesion efficiently controlled in most cases with doses below 20 Gy. However, sporadic failures may occur. A dose of 16 Gy is probably unsafe and should no longer be used. Future investigations should not only focus on total dosage of irradiation but also on fractionation schedules.

Endocrine function in patients treated for carcinoma in situ in the testis with irradiation

CIS is found in the contralateral testis in 5% of the patients with testicular germ cell cancer. The management of CIS in the contralateral testis is important because the majority - if not all - cases of CIS will progress to invasive disease without treatment. It is well documented that testicular irradiation with a total dose of 14-20 Gy (2 Gy x 7-10) is an effective and safe treatment for CIS in the contralateral testis in patients with unilateral testicular germ cell cancer. However few relapses of testicular cancer have been observed in testis treated with these regimens and the data on 14 Gy are sparse. One study has indicated that more radiotherapy with lower doses per fraction could be useful, but more data are needed to confirm this. Endocrine testicular function has been shown to be impaired already before treatment in patients with CIS and is further impaired after testicular irradiation with 14-20 Gy (2 Gy x 7-10) and only minor dose dependency is seen in the impairment of Leydig cell function. The optimal treatment of CIS in the contralateral testicle in patients orchidectomised for testicular cancer seems to be local radiotherapy of the testis with CIS in order to preserve at least a part of the Leydig cell function. However, the optimal dose level has to be defined.

Diagnosis and management of testicular intraepithelial neoplasia (carcinoma in situ)--surgical aspects

Germ cell tumours (CT) are no true carcinomas; therefore the term testicular intraepithelial neoplasia (IN) is probably more appropriate than "CIS". The diagnostic accuracy of a single-site biopsy is an open question. We experienced 9 false-negative biopsies among 1859 cases. Thus, the proportion of a failed diagnosis is 0.5%. The main reason for diagnostic failure is the non-random distribution of TIN within the testicle. Currently we are investigating whether a two-site biopsy is more accurate than a single biopsy. In the ongoing trial, the over-all prevalence of TIN is around 5.3%, so far. In one quarter of the positive cases the lesion was found in only one of the two specimens. Thus, a double biopsy appears to be more favourable than the traditional single biopsy. Surgical complications amount to 2.5% in that double biopsy study. Only one surgical re-intervention was required among 983 patients. Serial imaging studies with scrotal sonography and magnetic resonance imaging (MRI) disclosed a transient intratesticular haematoma/oedema postoperatively. So, testicular biopsy, even when performed at two sites is in fact a low-complication procedure. Low dose radiotherapy to the testis is the treatment of choice for TIN. However, more than one quarter of patients require testosterone supplementation secondary to androgen-deficiency. Two dose-reduction studies (Denmark and Germany) had to be terminated prematurely because unexpected relapse of TIN was encountered at 14 Gy and 16 Gy. Possibly, hyperfragmentation schedules can overcome the antagonism of androgenic compromise and oncological safety. In a nation-wide survey, it was shown that contralateral biopsies were routinely performed in 66% of the urological departments in Germany. Another 19% offered the biopsy to particular "risk-cases"; only 15% never did a biopsy. Among those refusing biopsies, there was a higher proportion of small hospitals and a significantly lower annual case-number of GCT, when compared to those doing the biopsy. Thus, the contralateral biopsy is a well-established procedure among German urologists; those with a high caseload of GCT particularly appreciate it.

Testicular germ cell cancer despite previous local radiotherapy to the testis

BACKGROUND

Testicular intraepithelial neoplasia (TIN, also carcinoma in situ of the testis) is the uniform precursor of testicular germ cell cancer. Local radiotherapy to the testis with dosages of 18-20 Gy has been found to safely eradicate TIN and germ cells, too. Thus, the general assumption is that the development of invasive germ cell tumours can be prevented by this radiotherapy.

PATIENTS AND METHODS

Herein, we report two patients with one-sided testicular tumour and biopsy-proven contralateral TIN. Both of them developed germ cell neoplasms in the remaining testis although local radiotherapy with 20 Gy had been applied to the testis.

RESULTS

One patient developed pure seminoma 7 years after completion of radiotherapy, the other developed a combined tumour consisting of embryonal carcinoma and seminoma after 5 years. Treatment consisted of orchiectomy in each of the cases. Histologically, both had TIN in the testicular tissue surrounding the new growths.

CONCLUSIONS

Pathogenetically, a small fraction of radioresistent TIN cells overcoming irradiation and progressing to full-blown germ cell cancer in the later course may be the histogenetic clue to explain these unexpected events. Other explanations, though less probable, could be technical radiotherapeutic failure due to targeting problems and a pre-existing radioresistent germ cell tumour in the irradiated testicle.