A Rare and Difficult-to-Detect Cervical Cancer: The Threat of Gastric-Type Adenocarcinoma in Women

Image source: Tzu Chi Hospital

Amid advances in HPV-based cervical cancer screening programs and Pap smear testing, there is a rare type of cervical cancer that often escapes detection. Known as gastric-type adenocarcinoma (GAS), this aggressive subtype of cervical cancer is not associated with Human Papillomavirus (HPV) infection. Recent studies indicate that this cancer carries a poor prognosis and is frequently diagnosed at an advanced stage.

Unlike most cervical cancers, which are linked to HPV infection, gastric-type adenocarcinoma develops through a different biological pathway. Since this cancer is not caused by HPV, standard HPV and Pap smear tests can appear normal even when the disease is already progressing. This makes gastric-type adenocarcinoma a major challenge for early diagnosis.

A systematic review involving 59 studies and 150 patients from various countries found that the average age at diagnosis was 52.8 years. The most common symptoms were abnormal vaginal bleeding and persistent vaginal discharge. However, in many cases, the early symptoms are subtle, leading patients to seek medical attention only after the disease has progressed to an advanced stage.

The study also revealed that approximately 28.7% of patients experienced cancer recurrence, with metastasis commonly occurring in distant organs such as the ovaries, peritoneum, liver, and abdominal lymph nodes. The five-year survival rate was only 26.7%, highlighting the highly aggressive nature of this disease compared with conventional cervical cancer.

From a histopathological perspective, gastric-type adenocarcinoma exhibits unique features resembling gastric tissue. Immunohistochemical markers such as MUC6, CK7, and p53 play an important role in supporting the diagnosis. Unfortunately, access to these advanced diagnostic tests are limited, particularly in developing countries.

In terms of treatment, radical hysterectomy becomes the primary option for patients diagnosed at an early stage. However, the response to conventional chemotherapy and radiotherapy is generally poorer than that observed in HPV-related cervical cancers. This highlights the need for more targeted therapeutic approaches specifically designed for gastric-type adenocarcinoma.

Researchers emphasize the importance of increasing clinical awareness of this rare subtype of cervical cancer, particularly among patients with persistent symptoms despite negative HPV screening results. Strengthening pathology diagnostic capacity and advancing molecular research are also essential to identify more effective treatments in the future.

Hence, gastric-type adenocarcinoma can escape routine screening, making early diagnosis and appropriate management crucial for improving patient survival.