Clear cell endometrial cancer: a CTF multicentre Italian study

Endometrial clear cell carcinoma (CCC) is a rare entity and only accounts for 1-6% of all endometrial cancers. CCC is considered an aggressive subtype of endometrial cancer with worse prognosis compared with type I cancer and more frequent relapses at distant and extrapelvic sites. These characteristics require specific treatment modalities, but rarity of the disease does not allow to identify evidence based indications for therapies. Objective of the present study is to analyse a series of cases treated in a multicentre Italian setting.

Sixty-five endometrial CCC were treated in the period 1990-2010 in the participating institutions. Slides of the pathological specimens were reviewed by a single pathologist of each institution and debatable cases were collegially reviewed. Clinical records were collected by a common database. Demographic, surgical pathological, and follow-up data were registered. Results: All patients received primary surgery. Stage of disease according FIGO 2009 was as follow: l a: 16.9%, lb: 35.4%, 2: 9.2%, 3a: 9.2%, 3b: 3.1%, 3c: 16.9%, 4a: 3.1%, and 4b: 6.1%. Adjuvant post-operative treatment was adopted in 53.8% of cases. A relapse was detected in 29.2% of cases with a majority of extrapelvic sites (68.4%). Five-year survival rate was significantly related to stage of disease with an excellent prognosis for Stage Ia e lb disease with a complete staging. In these cases adjuvant treatment does not show significant improvement of survival. Relapsed cases show a response rate to treatment in 26% of cases (predominantly chemotherapy).

CCC requires extensive surgical staging. Stage I disease completely staged does not require adjuvant therapy. More advanced stages require adjuvant chemotherapy.