The comparison of different treatments for women with Paget's disease of the vulva

Background
Extramammary Paget’s disease of the vulva is a rare type of superficial skin cancer. It is most common in postmenopausal white women. It is an intraepithelial (layer of cells that forms the surface or lining of an organ) condition that can present as white and red scaly areas on the vulva that may be itchy and painful. The diagnosis is made by examination and tissue sampling. Abnormal cells often extend outside the clinically abnormal area, so some studies suggest frozen section at time of surgery, where a pathologist can give a rapid report of small biopsies to say whether the skin is involved with Paget's or not. Other treatments include: topical medication, such as imiquimod (self-applied cream); radiotherapy; chemotherapy; photodynamic therapy (form of phototherapy using light-sensitive compounds that are exposed selectively to light, whereupon they become toxic to targeted cancerous and other diseased cells); laser therapy; or a combination of these approaches. The challenges of interventions are to remove or treat disease that may not be visible, without overtreatment. Avoiding the long-term complications of radical surgery, such as pain and scarring, a feeling of mutilation and loss of femininity, is very important to women. Surgery is still the most common treatment, but it is challenging to remove the disease completely, and recurrence is common, leading to repeated operations and mutilation of the vulva. The aim of this review was to evaluate the benefits and harms of different treatments for Paget's disease of the vulva.

Study characteristics
We searched for randomised controlled trials (trials where treatment is allocated to women in a random manner) and well-designed non-randomised studies that compared different treatments in women aged 18 years or older with biopsy-confirmed Paget's disease of the vulva.

Key results and quality of evidence
We searched scientific databases and contacted experts and identified and checked the titles and abstracts of 635 possibly relevant articles and retrieved 31 of these references in full text. However, we found no studies that met our inclusion criteria. We identified several non-randomised studies and drafted a detailed narrative of their results, but these studies were of poor quality and were at high risk of bias. Therefore, there is currently no evidence to determine whether any form of treatment is better or worse in terms of prolonging survival, delaying progression or recurrence, improving QoL or minimising toxicity. The review highlights the need for good-quality studies comparing different interventions for the management of Paget's disease of the vulva. Women and clinicians would value more evidence for guiding surgical and non-surgical management of this disease. In particular, non-invasive medical management would spare women from the side effects and consequences of surgery.

Authors' conclusions: 

Since the last version of the review was published there are many more cases in the literature reporting a clinical response to 5% imiquimod cream. There is one prospective study of eight women treated with 5% imiquimod for recurrent Paget's disease of the vulva, and one prospective trial of 20 women was due to be reported. This increasing evidence for the safety and efficacy of 5% imiquimod will be helpful for women and clinicians alike. Ideally, a multicentre RCT of reasonable size is needed, but ongoing publications of high-quality non-randomised prospective studies will enhance the current available literature.

Read the full abstract...
Background: 

This is an updated version of the original Cochrane Review published in Issue 10, 2013.

Extramammary Paget's disease is a rare form of superficial skin cancer. The most common site of involvement is the vulva. It is seen mainly in postmenopausal white women. Paget's disease of the vulva often spreads in an occult fashion, with margins extending beyond the apparent edges of the lesion. There is a range of interventions from surgical to non-invasive techniques or treatments. The challenges of interventions are to remove or treat disease that may not be visible, without overtreatment and with minimisation of morbidity from radical surgery. There is little consensus regarding treatment. Surgery, by default, is the most common treatment, but it is challenging to excise the disease adequately, and recurrence is common, leading to repeated operations, and destruction of anatomy. Alternative treatments of photodynamic therapy, laser therapy, radiotherapy, topical treatments or even chemotherapy have been mooted, and it is important to evaluate the available evidence. It is essential to assess whether newer cell-specific treatments, such as photodynamic therapy and imiquimod, can reduce the need for radical surgery.

Objectives: 

To evaluate the benefits and harms of different treatment modalities for the management of Paget's disease of the vulva.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (via Ovid) and Embase (via Ovid) up to 8 May 2018. We also searched registers of clinical trials, abstracts of scientific meetings and reference lists of review articles.

Selection criteria: 

We searched for randomised controlled trials (RCTs) and well-designed non-randomised studies that compared different interventions in women with Paget's disease of the vulva,

Data collection and analysis: 

Two review authors independently assessed whether potentially relevant studies met the inclusion criteria. We found no trials and, therefore, analysed no data.

Main results: 

The search for the original version of the review identified 635 unique references. We found 31 references (which reported on 30 studies) in full text after inspection of titles and abstracts, but we excluded them all as they did not meet the inclusion criteria. However, we have included a comprehensive narrative account of studies where we identified an analysis of more than 10 women, as this forms the only evidence base in this rare disease. Surgery continues to be the mainstay of treatment in the current literature, with other treatments limited to case reports or treatment of inoperable or recurrent disease.

This update between September 2013 and May 2018 identified 35 new studies. None of these met the inclusion criteria. There was only one prospective study of 5% imiquimod in recurrent Paget's disease of the vulva, which although of good quality only included eight women.