Role of adjuvant radiation or re-excision for early stage vulvar squamous cell carcinoma with positive or close surgical margins

Controversies in vulvar cancer: revisiting the margin of error

Despite an oftentimes radical surgical approach when treating patients with early-stage vulvar cancer, local recurrence occurs in approximately 40% of cases. Surgery in this setting can result in significant morbidity; however, treatment failure is associated with high mortality rates. Historically, many guidelines recommended a tumor-free margin ≥8 mm in the surgical treatment of vulvar cancer, although this is largely consensus-based and supported by a few small retrospective case series. Recently, numerous retrospective studies have found no association between a tumor-free margin of <8 mm and locoregional recurrence. Emerging evidence suggests that the presence of differentiated vulvar intra-epithelial neoplasia and lichen sclerosis at the pathologic margin may also play a role in local recurrence; however, data are retrospective and heterogenous, and the definition of what a "safe" tumor-free margin is remains unclear. However, increasing evidence has failed to demonstrate the beneficial role of re-excision or adjuvant radiation in the setting of margins of <8 mm. These additional treatments are associated with significant morbidity and have a negative impact on patients' quality of life; thus, they should be reserved solely for patients with positive margins. One of the main challenges in finding the ideal tumor-free margin is that the rarity of vulvar cancer makes prospective and randomized controlled trials difficult to conduct. Therefore, it is imperative that we make a concerted effort as a field to collaborate across nations and institutions, promote centralization of care for rare tumors, and prioritize future work to better understand the nature of this disease.

Vulvar Cancer: Histopathologic Considerations and Nuances to Management

Vulvar cancer, although rare, poses significant challenges in diagnosis and treatment because of its histopathologic complexities and nuances. This paper reviewed key aspects of the management of vulvar cancer, focusing on histopathologic diagnosis, margin status interpretation, lymph node involvement assessment, and ongoing clinical trials.

Systematic review - Adjuvant radiotherapy of the vulva in primary vulvar cancer

OBJECTIVE

Adjuvant radiotherapy to the vulva in vulvar squamous cell carcinoma (VSCC) is frequently performed albeit strong evidence is lacking. This systematic review aims to summarize the current literature on this topic.

METHODS

19 retrospective studies were included and analyzed, focusing on the primary outcome of local recurrence.

RESULTS

The publications present conflicting results. While the benefit of adjuvant radiotherapy to the groins in case of node-positive VSCC is well established, the indication criteria and effectiveness of adjuvant radiotherapy to the vulva remain unclear. Based on the studies included in this review, the current evidence suggests that adjuvant radiotherapy to the vulva might not significantly reduce the risk of recurrence or only in certain subgroups.

CONCLUSION

Most of the studies do not consider individual risk factors such as HPV status, resection margin, lymph node stage, grading and others. As a result, the comparability and reliability of these findings are limited. This review aims to highlight the need of further research addressing the risk stratification, considering both oncologic risk factors and adverse events.

Fertility-sparing treatment of locally advanced vulvar squamous cell carcinoma in a young patient

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Locally advanced vulvar cancer has been diagnosed in a young patient who desires fertility.

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Treatment of vulvar cancer in young patients will need to consider future reproductive planning.

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Fertility-sparing radiation techniques for treatment of vulvar cancer are effective in achieving long-term disease control.

Management of Early-Stage Vulvar Cancer

Simple Summary

Vulvar cancer is a rare gynecological malignancy that affects mainly postmenopausal women. Recently, however, an alarming increase in the rates among young women has been observed due to human papillomavirus infection. The standard treatment for vulvar cancer is surgery with or without radiotherapy as adjuvant treatment. In recent decades, sentinel lymph node biopsy has been included as part of the surgical treatment. Thus, our objective was to review and discuss the advances found in the literature about early-stage vulvar cancer. For this, we searched PubMed for publications in the English language. Relevant articles, such as the GROINS-V studies, and the GOG protocols, are presented in this review exhibiting the evolution of early-stage vulvar cancer treatment and the decrease in surgical morbidity rates.

Abstract

Vulvar cancer is a rare gynecological malignancy since it represents 4% of all cancers of the female genital tract. The most common histological type is squamous cell carcinoma (90%). This type can be classified into two clinicopathological subtypes according to the etiology. The first subtype is associated with persistent human papillomavirus infection and is usually diagnosed in younger women. The second subtype is associated with lichen sclerosus condition, and in most cases is diagnosed in postmenopausal women. Currently, an increase in first subtype cases has been observed, which raised the concern about associated mortality and treatment morbidity among young women. Vulvar cancer treatment depends on histopathology grade and staging, but surgery with or without radiotherapy as adjuvant treatment is considered the gold standard. In recent decades, sentinel lymph node biopsy has been incorporated as part of the treatment. Therefore, we sought to review and discuss the advances documented in the literature about vulvar cancer focusing on the treatment of early-stage disease. Relevant articles, such as the GROINS-V studies and the GOG protocols, are presented in this review. Additionally, we discuss key points such as the evolution of treatment from invasive surgery with high morbidity, to more conservative approaches without compromising oncologic safety; the role of sentinel lymph node mapping in the initial staging, since it reduces the complications caused by inguinofemoral lymphadenectomy; the recurrences rates, since local recurrence is common and curable, however, groin-associated, or distant recurrences have a poor prognosis; and, finally, the long-term follow-up that is essential for all patients.

Postoperative management of vulvar cancer

The primary treatment for resectable vulvar cancer includes wide local excision of the primary tumor and surgical lymph node assessment. Following surgery, up to 40-50% of patients develop a local recurrence. Historically, the strongest predictor of local recurrence is a positive or close margin (defined as <8 mm), although recent studies question the importance of margin status. Post-operative radiotherapy to the vulva is recommended for all women with a positive margin where re-excision is not possible. Radiotherapy may also be considered in the setting of risk factors for local recurrence: close margin, lymphovascular invasion, large tumor size, and/or depth of invasion >5 mm. Nodal assessment is an important component of vulvar cancer management. A negative sentinel node is associated with a low false-negative predictive value (2% in patients with vulvar tumor <4 cm in GOG 173), 2-year groin recurrence rate of 2.3%, and 3-year disease-specific survival rate of 97% in patients with unifocal vulvar tumor <4 cm in the GROningen INternational Study on Sentinel nodes in Vulvar Cancer (GROINSS-V I) study. Thus, patients with tumor size <4 cm (without additional local risk factors) and negative sentinel node can be observed. Patients with sentinel node metastasis ≤2 mm can be treated with post-operative radiotherapy (2-year isolated groin recurrence rate of 1.6% in GROINSS-V II), as a safe alternative to lymphadenectomy. Patients with sentinel node metastasis >2 mm following sentinel node biopsy should undergo inguinofemoral lymphadenectomy followed by post-operative radiotherapy-based on the GROINSS-V II study, the 2-year isolated groin recurrence rate remains unacceptably high (22%) with radiotherapy alone. Retrospective studies suggest that the addition of concurrent chemotherapy to radiotherapy may improve survival. The ongoing GROINSS-V III study is investigating concurrent chemotherapy and radiotherapy dose escalation. The main goal of these post-operative treatments is to reduce the risk of local, and especially groin, recurrences, which are almost universally fatal.

Positive surgical margin is an independent predictor of overall survival of patients with vulvar squamous cell carcinoma

AIM

It is uncertain whether curative surgical treatment or a less radical surgery with adjuvant treatment should be provided to preserve function in patients with vulvar squamous cell carcinoma (SCC) that is adjacent to the urethra, anus, and vagina. The aim of this study was to investigate the surgical margin in patients with vulvar SCC with regard to local recurrence and overall survival.

METHODS

Thirty-four patients were identified as having a diagnosis of vulvar SCC without distant metastasis. They had been treated surgically with curative intent at the Cancer Institute Hospital. Clinical data were analyzed retrospectively.

RESULTS

Rates of 5-year local recurrence-free survival among patients with positive, <3-mm, <5-mm, <8-mm, and ≥8-mm surgical margins were 32%, 30.3%, 42.5%, 55.5%, and 73%, respectively. Rates of 5-year overall survival of patients with positive, <3-mm, <5-mm, <8-mm, and ≥8-mm surgical margins were 15.5%, 53.8%, 58.8%, 67.6%, and 83.3%, respectively. In the multivariable analysis, a tumor size of more than 2-cm (hazard ratio [HR] = 17.7, 95% confidence interval [CI] = 1.39-226) and a positive surgical margin (HR = 0.0092, 95% CI = 0.011-0.53) were risk factors for local recurrence, and a lymph node involvement (HR = 1.41, 95% CI = 0.31-6.43) and a positive surgical margin (HR = 0.0046, 95% CI = 0.011-0.53) were significant risk factors for overall mortality.

CONCLUSIONS

To improve the prognosis, thorough resection with an adequate surgical margin is needed. But narrow surgical margin may be acceptable, particularly to preserve the function of adjacent organs.

Reducing the radicality of surgery for vulvar cancer: are smaller margins safer?

INTRODUCTION

Vulvar cancer accounts for ~4% of all gynecological malignancies and the majority of tumors (>90%) are squamous cell (keratinizing, ~60% and warty/basaloid, ~30%). Surgical excision forms the foundation of treatment, with resection margin status being the single most influential factor when predicting clinical outcome. There has been a paradigm shift concerning surgical approaches and radicality when managing vulvar cancer within recent times, largely owing to a desire to preserve vulvar structure and function without compromising oncological outcome. As such the safety of the size of resection margin has been called into question. In this narrative review we consider the current literature on the safety of resection margins for vulvar cancer.

EVIDENCE ACQUISITION

PubMed, Medline and the Cochrane Database were searched for original peer-reviewed primary and review articles, from January 2005 to January 2020. The following search terms were used vulvar cancer surgery, vulvar squamous cell carcinoma, excision margins, adjuvant radiation.

EVIDENCE SYNTHESIS

A pathological tumor margin of <8 mm has been widely considered to indicate "close" margins. This measurement after fixation of the tumor is considered comparable to a surgical resection margin of around 1cm, following an estimated 20% tissue shrinkage after formalin fixation and a 1-2cm clinical surgical margin in order to achieve the 8 mm final pathological margin.

CONCLUSIONS

A surgical resection margin of 2-3mm does not appear to be associated with a higher rate of local recurrence than the widely used limit of 8 mm. As such the traditional practice of re-excision or adjuvant radiotherapy based on "close" surgical margins alone needs to be closely evaluated, since the attendant morbidity associated with these procedures may not be outweighed by oncological benefit.

The Prognostic Role of the Surgical Margins in Squamous Vulvar Cancer: A Retrospective Australian Study

For the last 30 years at the Royal Hospital for Women, unifocal vulvar squamous cancers have been treated by radical local excision, aiming to achieve a histopathological margin of ≥8 mm, equating to a surgical margin of 1 cm. The need for a margin of this width has recently been challenged. We aimed to determine the long-term outcome following this conservative approach, and the relationship between vulvar recurrences and surgical margins. Data were obtained retrospectively on 345 patients treated primarily with surgery for squamous vulvar cancer between 1987 and 2017. Median follow-up was 93 months. Five-year disease-specific survival was 86%. Of 78 vulvar recurrences, 33 (42.3%) were at the primary site and 45 (57.7%) at a remote site. In multivariable analysis, a margin < 5 mm showed a higher risk of all vulvar (Hazard ratio (HR), 2.29; CI, 1.12-4.70), and primary site recurrences (subdistribution hazard ratio (SHR), 15.20; CI, 5.21-44.26), while those with a margin of 5 to <8 mm had a higher risk of a primary site recurrence (SHR, 8.92; CI, 3.26-24.43), and a lower risk of remote site recurrence. Excision margins < 8 mm treated by re-excision or radiation therapy had a significantly decreased risk of recurrence. Guidelines should continue to recommend a surgical margin of 1 cm.

Tumor-free margins and local recurrence in squamous cell carcinoma of the vulva

OBJECTIVE

To investigate the relation of pathologic tumor-free margins and local recurrence in patients who underwent primary surgery for vulvar squamous cell carcinoma.

METHODS

In this retrospective analysis, patients with stage I-III vulvar squamous cell carcinoma who underwent primary surgery between 2000 and 2018 were identified from the Mayo Clinic Cancer Registry.

RESULTS

A total of 335 patients were included and divided into three groups according to tumor-free margins: group 1 (<3 mm, n = 32); group 2 (≥3 to <8 mm, n = 151); group 3 (≥8 mm, n = 152). The median follow-up time was 73 months (range 2-240). A total of 78 (23.3%) patients developed local recurrence. With the inverse propensity score weighing method adjusting baseline characters, margins <8 mm had inferior local control (HR 1.98, 95% CI 1.13-3.41). The 5-year local disease-free survival (DFS) was 48.2%, 81.5% and 84.6% for group 1, 2 and 3 respectively (p < 0.001). There were no differences in groin lymph nodes relapse (p = 0.850), distant metastases (p = 0.253), or disease-specific survival (DSS) (p = 0.289) among the three groups. Margins <8 mm, midline involvement, multifocal disease, precancerous lesions on margins and depth of invasion >1 mm were found to be poor prognosticators for local DFS in univariate analysis. Multifocal disease was the strongest predictor for local recurrence in multivariate analysis (HR 4.32, 95% CI 2.67-6.99).

CONCLUSION

Patients undergoing primary surgery for vulvar squamous cell carcinoma with tumor free-margins <8 mm have a higher local recurrence rate.