A rare, but aggressive, malignant transformation occurs at higher rates in endometriosis patients who underwent cesarean section, a review study shows.
The phenomenon, known as endometriosis-associated malignant transformation in abdominal surgical scar (EAMTAS), evolves slowly and is diagnosed many years after surgery (from 4 to 41 years), according to the data.
The review “Endometriosis-associated malignant transformation in abdominal surgical scar: A PRISMA-compliant systematic review” was published in the journal Medicine.
To further understand the risk factors for EAMTAS and how it affects patients’ overall survival, a group of researchers performed a systematic review of published studies from 1980 to 2016.
They identified 47 case-report studies from the literature and included one more case from their own institution, the Assaf-Harofeh Medical Center, in Tel Aviv, Israel. The final analysis included 48 patients. For seven of these studies, they received updated information on the patients’ follow-up from the investigators in charge.
Patients were on average 46 years old and all had a uterine surgery. The majority had a cesarean section (87.5%), while the rest (12.5%) had other gynecological surgery, most often a laparotomy (a surgical procedure to obtain access into the abdominal cavity).
While endometriosis is generally a benign condition, it may be associated with malignant transformation, the most common type being uterine clear-cell carcinoma. Accordingly, this type of cancer also was the most common in EAMTAS patients: 32 patients (66.7%), followed by seven cases of endometrioid carcinoma (14.6%). Other cancer types identified included serous papillary carcinoma, adenocarcinoma, sarcoma, and a mix of several other types.
The most frequent forms of treatment included extensive surgery – performed in 95.8% of patients – followed in some cases by neoadjuvant chemotherapy. Nineteen patients underwent radiotherapy after the surgery and chemotherapy.
Patients overall 5-year survival was 40%, with a median overall survival of 3.5 years.
Although the study is one of the largest in the literature, the number of patients is not enough to perform statistical analysis, authors explained.
Overall, “EAMTAS is a rare and aggressive disease. It is mostly related to cesarean section scars and is diagnosed many years postsurgery. Clear-cell histology tends to endure from the worse prognosis. The treatment is mainly extensive surgery and adjuvant chemotherapy and/or radiotherapy,” the study concluded.
Further studies are needed so that patients have better screening strategies for detecting this rare phenomenon and to develop more efficient treatments, the reviewers wrote.