The case for nonsurgical therapy of nonmetastatic penile cancer

Brachytherapy and external beam radiation in the management of primary penile cancer - Game changer for organ preservation?

OBJECTIVE

In squamous cell carcinoma of the penis (PeCa), treatment options for primary tumors vary by disease stage and may include surgery, radiation, topical chemotherapy, or laser excision. This review aims to highlight the current evidence on the value of radiotherapy as an organ-preserving strategy in primary PeCa.

MATERIAL AND METHODS

Manuscripts on primary PeCa treatment with external beam radiotherapy (EBRT) and brachytherapy were evaluated via Scopus, PubMed/MEDLINE, and Web of ScienceTM (2013-2023) to assess their efficacy and safety. Animal studies, studies with <5 patients, and case reports were excluded.

RESULTS

Radiotherapy offers the potential for organ preservation with tumor control rates comparable to radical surgery, while disease-specific survival rates up to 70 % were experienced with EBRT. Brachytherapy (BT) is the preferred method of irradiation for glans-limited tumors, whereas a higher relapse risk is expected for tumors >4 cm. BT shows 73 % amputation-free survival at 8-10 years and 81 % progression-free survival at 5-10 years. Compared with BT, total amputation significantly improves 5-year disease-free survival rate. BT offers a superior 5-year local control and penile preservation rates compared to EBRT. Common acute toxicities of brachytherapy include radiodermatitis, sterile urethritis, and urethral adhesions. The primary late adverse events of BT are soft tissue necrosis (0-31 %) and meatal stenosis (0-43 %).

CONCLUSION

BT is a favorable radiation modality, offering an efficient and conservative approach. HDR BT is favored for its enhanced dose distribution and radiation protection. Collaboration between radiation oncologists and urologists is essential in order to provide an optimal patient selection and manage toxicities thus optimizing patient outcomes.

The role of radiotherapy in the management of squamous cell cancer of the penis

PURPOSE

To review the evidence for radiotherapy in the management of primary penile cancer, either as brachytherapy or external beam radiation, and the role of external beam radiotherapy in node positive penile cancer.

METHODS

English language literature was reviewed for the past 3 decades. As penile cancer is uncommon in developed nations, high quality evidence to guide management is limited. Single institution reports often span decades during which time staging systems and treatments have evolved, reducing their relevance to current practice. Successful clinical trials require collaboration not only among disciplines but also among multiple institutions and nations.

RESULTS

Radiotherapy is a definitive organ-preserving option for T1-T2 penile cancers. Interstitial brachytherapy is associated with penile preservation in 85% of men at 5 years, maintained in 70% by 10 years. Results of external radiotherapy are not quite as promising but nonetheless 60% of men will have an intact penis at 5 years. Inguino-pelvic external radiotherapy has been reported to increase overall survival when delivered as adjuvant treatment for men with pN3 groin but pN0 pelvic nodes, and improve disease specific survival for those with involved pelvic nodes. InPACT (ECOG-ACRIN_8134) is investigating the role of inguino-pelvic chemo-radiotherapy for men with pN3 inguinal nodes but imaging negative pelvic nodes.

CONCLUSIONS

Radiotherapy has a well-defined role to play in treatment of squamous cell cancers of other sites, such as vulva, anal canal, uterine cervix and head and neck malignancies. Emerging data support the incorporation of radiotherapy into treatment paradigms for penile cancer.

Organ-sparing treatment for T1 and T2 penile cancer: an updated literature review

PURPOSE OF REVIEW

Penile cancer (PeCa) is an orphan disease due to its rare incidence in high-income countries. Traditional surgical options for clinical T1-2 disease, including partial and total penectomy, can dramatically affect patient's quality of life and mental health status. In selected patients, organ-sparing surgery (OSS) has the potential to remove the primary tumor with comparable oncologic outcomes while maintaining penile length, sexual and urinary function. In this review, we aim to discuss the indications, advantages, and outcomes of various OSSs currently available for men diagnosed with PeCa seeking an organ-preserving option.

RECENT FINDINGS

Patient survival largely depends on spotting and treating lymph node metastasis at an early stage. The required surgical and radiotherapy skill sets cannot be expected to be available in all centers. Consequently, patients should be referred to high-volume centers to receive the best available treatments for PeCa.

SUMMARY

OSS should be used for small and localized PeCa (T1-T2) as an alternative to partial penectomy to preserve patient's quality of life while maintaining sexual and urinary function and penile aesthetics. Overall, there are different techniques that can be used with different response and recurrence rates. In case of tumor recurrence, partial penectomy or radical penectomy is feasible, without impacting overall survival.

Management of Advanced Penile Cancer

Penile squamous cell carcinoma (PSCC) is a rare cancer, with approximately 2000 new cases in the United States and 35,000 globally every year. Multiple risk factors are involved in PSCC, but most importantly, the high-risk human papillomavirus infection is thought to be present in approximately 50% of cases. Penile squamous cell carcinoma presents as localized or locally advanced disease. Multiple prognostic markers have been explored over the past 3 decades, but lymph node status remains the strongest predictor of clinical outcomes. Surgical decisions are based on the primary tumor pathologic findings, nodal clinical examination, and imaging results. Most patients with high-risk advanced PSCC benefit from a multimodal treatment approach combining chemotherapy with consolidation surgical treatment. The role of neoadjuvant chemotherapy with radiation therapy has not been well explored in PSCC. Prospective clinical studies, like the International Penile Advanced Cancer Trial, have been launched to provide high-level evidence for multimodal treatment. The International Penile Advanced Cancer Trial is the first randomized clinical trial among patients with PSCC and is currently accruing, with the expectation to generate results in 2023. Unfortunately, most patients with high-risk locally advanced PSCC will have relapsed or refractory cancer after cisplatin-based combination chemotherapy. These patients have dismal outcomes with salvage chemotherapy, highlighting the major unmet need to expand our knowledge of the disease's biology and develop clinical trials that use novel systemic agents. This narrative review synthesizes relevant publications retrieved from PubMed. Our aim is to discuss current approaches in the management of PSCC, summarize ongoing efforts to improve care, and identify future areas for enhancing our understanding of the disease.

Organ preserving radiation strategies for penile cancer

INTRODUCTION

The majorities of penile cancers are of squamous cell origin and thus are amenable to treatment and cure by radiation. Despite the move toward penile sparing strategies, radiation remains an under-utilized and often neglected option. This paper will review the various radio-therapeutic approaches for penile cancer and the literature supporting their use. English, French and Spanish literature on penile cancer was reviewed for the past 5 decades and classified according to modality: external beam radiotherapy, interstitial brachytherapy and surface mold brachytherapy. Many series span several decades and include a wide range of stages, especially for external beam radiotherapy. Penile preservation obviously will depend on dose prescription and stage at treatment. Nonetheless, in general, penile sparing with external beam ranges from 36% to 66% at 5 years. For the selected patients appropriate for interstitial brachytherapy penile sparing is 77% to 87% at 5 years, decreasing to 70% at 10 years. Mold therapy is selected for those with very superficial disease and penile sparing is consequently higher.

CONCLUSIONS

The development of centers of excellence for the management of this uncommon disease is encouraged. The required surgical and radiotherapy skill sets cannot be expected to be available in all centers. A multidisciplinary evaluation of each patient will facilitate selection of optimal management from the outset.

[Systemic treatment of locally advanced or metastatic penile cancer]

Penile cancers are rare, the vast majority is represented by squamous cell carcinoma, with HPV virus being found in 30 to 40% of cases. At a locally advanced or metastatic stage, first-line treatment relies on platinum and taxane based polychemotherapy. The prognosis for advanced or metastatic penile cancer remains poor, with overall survival ranging from 13.9 to 17.1 months. After the first line, guidelines recommend various chemotherapy treatments or targeted anti-EGFR therapies whose results as well as the level of evidence are limited. A better understanding of the oncogenic pathways involved in penile cancer and a frequent expression of PD-L1 are the rationale for the elaboration of new strategies. This review article presents the data, guidelines and ongoing studies in locally advanced or metastatic penile cancer.

Definitive Chemoradiotherapy for Locally Advanced, Lymph-node Positive, Nonmetastatic Penile Squamous Cell Carcinoma

INTRODUCTION

Locally advanced penile cancer is rare, with few reported studies on the therapeutic role of chemoradiotherapy. We sought to characterize the efficacy and toxicity of definitive chemoradiotherapy for locally advanced, node-positive, squamous cell carcinoma of the penis.

MATERIALS AND METHODS

Six patients who had refused or were ineligible for surgical resection of clinically staged node-positive squamous cell penile cancer were treated with definitive chemoradiotherapy using either weekly cisplatin or 2 cycles of mitomycin C/5-fluorouracil. The mean radiation dose to the primary sites, involved lymph nodes, involved nodal basins, and uninvolved nodal basins was 57.2, 55.0, 49.7, and 42.3 equivalent dose delivered in 2-Gy fractions.

RESULTS

With a median follow-up of 7.2 years, 4 of the 6 patients were recurrence-free and 2 had developed recurrence. One of the latter died of penile-specific complications after salvage surgery to treat the recurrence. Of the 6 patients, 4 experienced long-term penectomy-free survival. No patient developed distant metastasis after therapy. The 4 patients with durable penectomy-free survival reported excellent urologic, sexual, and bowel function, as assessed by various validated patient-reported outcome surveys and subjective reports. One of the 2 patients with recurrence was successfully salvaged with penectomy. Lymphedema and stricture were not reported by any of the patients.

CONCLUSIONS

Definitive chemoradiotherapy is an effective organ-sparing treatment of node-positive penile cancer, with durable disease control and maintenance of quality of life. This treatment option should be offered to carefully counseled patients within the context of expert multidisciplinary teams and should be incorporated into expert consensus treatment guidelines.

High-dose-rate brachytherapy for localized penile cancer: Evolution of a technique

PURPOSE

High-dose-rate (HDR) brachytherapy is a convenient treatment option for selected patients with T1-T2 penile squamous cell carcinoma (SCC), providing high rates of penile preservation and tumor control. We present the results of penile SCC treated with HDR brachytherapy either interstitially or via a surface mold.

METHODS AND MATERIALS

Between November 2009 and April 2019, seven patients (2 T1a and 5 T2) were treated with interstitial HDR and 8 (1 Tis, six T1a, and one T1b) with surface mold. Prescribed dose for interstitial patients ranged from 38.4 Gy in 6 days (3.2 Gy × 12) to 53 Gy in 9 days (3.12 × 17), BID. All patients treated with mold brachytherapy received 40 Gy in 10 fractions BID. Toxicity and oncological results were assessed for both groups, and their relation with dosimetry is described.

RESULTS

Median follow up was 90 months for interstitial and 27 months for those treated with surface mold. Fourteen of 15 patients are alive and disease-free; one surface mold patient died of non-small-cell lung cancer. There was one relapse in each group, each treated with salvage penectomy. The potency was preserved in 82%. For interstitial, G2 necrosis occurred in 43%, G2 meatal stenosis in 29% and G3 stenosis in 14%.

CONCLUSIONS

Both techniques have excellent rates of tumor control and organ preservation. Implant geometry and homogeneity constraints must be carefully designed to minimize toxicity in interstitial brachytherapy. Urethral contouring and reporting of dosimetric parameters should be defined.