The uterus is a part of the female reproductive system responsible for the growth and development of the fetus. The inner lining of the uterus is the endometrium.
Endometrial cancer, or endometrial carcinoma, occurs when the endometrium cells start to grow and multiply uncontrollably. It is one of the most common cancers affecting the female reproductive system. It is a type of uterine cancer. The other type is uterine sarcoma, which involves the muscles and connective tissues of the uterus.
Unlike most cancers, the diagnosis of endometrial (uterine) cancer occurs early due to the presentation of symptoms. Thus, the treatment and prognosis of endometrial carcinoma are favorable. Endometrial adenocarcinomas constitute about 80% of all endometrial cancers in the endometrial glands.
Endometrial cancer is one of the most common cancers in women, and the number of cases is increasing. The data from the World Health Organization in 2020 reported endometrial cancer as the 6th most common cancer in women, ranking endometrial carcinoma at 15th among overall cancers.
There is also an increased incidence of this cancer type in India. This rise in endometrial carcinoma in India is attributed to changing trends in the reproductive profile and lifestyle of women in India, particularly in urban areas.
Based on the type of cell type from which it originates, endometrial carcinoma is classified into various types. The following are the different types of endometrial cancer are:
The most common types of endometrial cancer are:
It is one of the most common endometrial cancers and constitutes about 85–90% of the cases. The condition usually affects women between the ages of 55 and 65. It is also called the type 1 uterine carcinoma. It has a slow progression rate. Patients with endometrial adenocarcinoma have a relatively favorable prognosis.
Previously called malignant mixed Müllerian tumors, uterine carcinosarcomas are rare and highly aggressive tumors. Uterine carcinosarcoma has a low survival rate, with a 5-year survival rate of 38%. When histologically examined, these tumors have the features of both sarcoma and carcinoma.
It is one of the endometrial cancer types, and it accounts for only 5% of all endometrial cases. It has a variable degree of differentiation.
It is an aggressive cancer similar to the small-cell cancer of the lungs. Patients with this condition experience abdominal pain and abnormal vaginal bleeding.
Transitional cell carcinoma is one of the variants of endometrial carcinoma and has distinctive immunophenotypic and histological features. It is a rare occurrence.
The condition is characterized by abnormal p53 staining in immunohistochemistry, accounting for almost 20% of endometrial carcinomas. However, the mortality rate for serous carcinoma is high, standing at 74%.
The following are the less common endometrial cancer types:
It is one of the rare and aggressive endometrial cancer types. Approximately 45% of the cases have extrauterine growth at diagnosis.
It is a rare type of endometrial cancer. There is a challenge in diagnosing this condition due to the varied morphology of the endometrium.
Endometrial cancer staging is a significant step in endometrial cancer management. Staging helps the specialist in assessing the extent of the disease’s spread. Determining the stage of endometrial carcinoma plays a pivotal role in devising a customized treatment plan and effectively managing the disease.
Stage 1 endometrial cancer is divided into stage 1A and stage 1B.
During stage 1A, the cancer is present in the inner uterine lining and has invaded less than half of the uterine muscle layer.
During stage 1B, the cancer has spread over half of the myometrium (uterine muscles) but has not invaded beyond the uterine body. The cancer at stage 1 does not spread to the lymph nodes or distant organs.
In stage 2, cancer of the endometrium has spread to the uterine body and invaded the supporting cervical connective tissue (cervical stroma). However, the cancer has not spread outside the uterus, to the lymph nodes and distant organs.
Stage 3 endometrial cancer is subdivided into 3A, 3B, 3C1, and 3C2.
Stage 3A is characterized by the spread of cancer to the outer uterine surface and/or to the ovaries or the fallopian tubes.
Stage 3B involves spreading the malignant cells to the vagina or the tissues surrounding the uterus (parametrium).
Stage 3C1 involves the growth of tumors in the uterine body and some surrounding tissues. However, it does not invade the rectum or bladder. The cancer may invade pelvic lymph nodes but not aortic lymph nodes.
Stage 3C2 involves the growth of the cancer into the uterine body. It has not grown into the rectum or bladder. The cancer has spread to the aortic lymph nodes. Stage 3 endometrial cancer does not spread to distant sites.
Stage four endometrial cancer is divided into stages 4A and 4B.
In the 4A stage, the cancer invades the inner lining of the urinary bladder of the rectum. The cancer may have spread to the nearby lymph nodes but not to the distant organs.
In the 4B stage, the cancer has spread to the omentum, upper abdomen, groin lymph nodes, or distant organs, such as the lungs, liver, or bones. The cancer may or may not spread to the other lymph nodes.
Endometrial cancer initiates in the endometrium and is one of the most common cancers of the female reproductive system. The incidence of this cancer is rising in India. Some common types of endometrial carcinoma are endometrioid adenocarcinoma, small cell carcinoma, squamous cell carcinoma, uterine carcinosarcoma, serous carcinoma, and transitional carcinoma. Stage 1 refers to the early-stage, and stage 4 is the late-stage endometrial cancer.