29. Endometrial Cancer Flashcards
4th most common cancer in American women and most commonly encountered gynecologic malignancy in the U.S.
Endometrial Cancer
(associated with a favorable survival profile b/c majority of disease is diagnosed early)
Two distinct pathogenic etiologies of endometrial cancer
-
Type I (80%) –> occurs in women w hx of chronic estrogen exposure unopposed by progestin (estrogen-dependent neoplasms)
- Tumors tend to be well differentiated (endometrioid type with lower grade nuclei and usually have a more favorable prognosis)
-
Type II (20%) –> estrogen INdependent neoplasm
- High-grade nuclear atypia with serous or clear cell histology
- Many associated with a mutation in the p53 TSG
What is an important component in the staging and prognosis of endometrial cancer?
Depth of myometrial invasion
The prognosis is dramatically worsened when the cancer has invaded more than 1/2 of thickness of myometrium
Endometrial carcinoma has four primary routes of spread.
- Direct extension of the tumor downward to the cervix or outward through the myometrium and serosa
- Lymphatic spread to pelvic and para-aortic lymph nodes when there is significant myometrial penetration
- Exfoliated cells may also shed transtubally through fallopian tubes to the ovaries, parietal peritoneum, and omentum
- Hematogenous spread occurs less frequently, but can result in metastasis to the liver, lungs and/or bone
What is the most common type of endometrial cancer?
What is the most important prognostic factor?
Endometrioid adenocarcinoma (75-80%):
proliferation of glandular cells of the endometrium
Other nonendometrioid tumor types:
Mucinous carcinoma (5%)
Clear cell carcinoma (5%)
Papillary serous carcinomas (4%)
Squamous carcinomas (1%)
Most imp prognostic factor = histologic grade
High-grade tumors have a much poorer prognosis due to likelihood of spread outside of the uterus.
Major independent prognostic factors for endometrial cancer
- Age
- Depth of myometrial invasion
- Histologic grade
- Histologic type
- Surgical stage
- Peritoneal cytology
- Tumor size
- Lymphovascular invasion
- Pelvic lymph node mets
Epidemiology
Endometrial cancer occurs in both premenopausal (25%) and postmenopausal (75%) women.
Avg age of dx = 61
Most tumors caught during low-grade stage (Stage I = 72%)
Risk Factors for Endometrial Cancer
Are these screening mechanisms for type I endometrial cancer?
No
Neither annual Pap smears nor endometrial biopsies have been shown to offer cost-effective screening in asymptomatic pts.
Protective factors that decrease lifetime estrogen exposure
- Combination OCPs
- Progestin-containing contraceptives
- Combination E+P HRT
These pts have a lower rate of endometrial cancer compared with nonusers. The protection conferred on a woman who takes combo OCPs lasts for 15 yrs after discontinuation.
- High parity
- Pregnancy
- Physical activity (dec. obesity, favorable immune fxn, endogenous hormone levels)
- Smoking
- Causes increased hepatic metabolism of estrogen
- Avoid obesity, HTN, and dM
Are there identifiable risk factors for women who may be at risk for type II endometrial cancer?
No
Clinical manifestations:
Physical exam:
(what to look for)
Postmenopausal bleeding***
Advanced stage:
pelvic pain, pelvic mass, weight loss
Physical exam:
obesity, acanthosis nigricans, HTN, stigmata of diabetes
… also look for signs of metastatic disease (including pleural effusion, ascites, hepatosplenomegaly, general lymphadenopathy, and abdominal masses)
Differential Dx of Postmenopausal Bleeding
Diagnostic evaluation of irregular bleeding
EMB (accuracy of 90% to 98%)
If thickness is 4 mm or less… indicative of low risk for malignancy
+TSH, prolactin (if oligomenorrheic), FSH, estradiol level (to distinguish whether pt is menopausal)
+CBC (to r/o anemia preop)
+CA-125 (to assess for spread beyond uterus)
More than 50% of women at risk for Lynch II syndrome (or HNPCC) will develop endometrial and/or ovarian cancer before developing colon cancer.
Best plan of action?
if pt has family member known to carry such a mutation, pt should undergo yearly EMB beginning at age 35
Treatment:
- Systematic surgical staging, including total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH-BSO)
- Pelvic washings
- Pelvic and para-aortic lymph node resection
- Complete resction of visible tumor for all stages of disease
Surgical Staging of Endometrial Carcinoma
