What is the recommended treatment for well-differentiated endometrial adenocarcinoma limited to the inner half of the myometrium?

Treatment of Well-Differentiated Endometrial Adenocarcinoma Limited to Inner Half of Myometrium

For well-differentiated endometrial adenocarcinoma limited to the inner half of the myometrium (FIGO stage Ib, grade 1), perform total hysterectomy with bilateral salpingo-oophorectomy without adjuvant therapy—this is low-risk disease with excellent prognosis and no survival benefit from additional treatment. 1, 2

Surgical Management

Primary surgical treatment consists of:

• Total hysterectomy with bilateral salpingo-oophorectomy as the definitive treatment 3, 1
• Peritoneal washings or fluid collection at the time of surgery 3, 1
• Thorough exploration of the abdominal cavity and pelvic/para-aortic nodal areas 3, 1
• Lymphadenectomy is NOT recommended for this low-risk presentation, as it provides no survival benefit and only increases morbidity (lymphedema risk) without therapeutic value 1, 2

The surgery can be performed via open or laparoscopic approach 3. This patient population—stage Ia/Ib, grade 1-2, endometrioid histology—represents the low-risk category with approximately 93-94% five-year disease-free survival after surgery alone 1, 4.

Adjuvant Therapy Decision

No adjuvant therapy is indicated for this low-risk disease. 3, 1, 2

The evidence is clear on this point:

• Adjuvant pelvic radiotherapy reduces pelvic/vaginal relapses but has no impact on overall survival in stage I disease 3
• Radiotherapy is reserved for intermediate-risk patients (those with two of three major risk factors: age ≥60 years, deeper myometrial invasion, or lymphovascular space invasion) 3, 2
• Progestational agents do not increase survival in low-stage endometrial cancer and are not recommended 3, 1

Risk Stratification Context

Your patient falls into the low-risk category based on FIGO staging 3:

• Stage Ib = invasion to less than one-half (inner half) of the myometrium 3
• Grade 1 (well-differentiated) = non-squamous, non-morular solid growth pattern comprises ≤5% of the tumor 3
• Endometrioid histology (assumed, as this represents 80% of cases) 3

This combination confers excellent prognosis with recurrence rates of only 2-10% 4.

Surveillance Strategy

Post-surgical surveillance should include:

• Physical and gynecological examination every 3-4 months for the first 2-3 years 1, 4
• Every 6 months during years 4-5 1, 4
• Annually thereafter 1, 4

Do NOT routinely order:

• CT scans, chest X-rays, or PET scans in asymptomatic patients (detection rates only 0-20%) 4
• CA-125 levels (negligible utility in low-risk disease) 4
• Vaginal cytology has poor sensitivity (0-7% detection rate) but may be considered every 6 months initially 4

Critical patient education: Counsel patients to immediately report vaginal bleeding, pelvic pain, unexplained weight loss, or persistent cough, as 41-83% of recurrences are detected symptomatically rather than by surveillance testing 4.

Special Circumstances

For young women desiring fertility preservation:

• Conservative management with high-dose progestin therapy may be considered in highly selected cases 2, 5
• This requires: grade 1 disease, no myometrial invasion (stage Ia only), absence of metastatic disease on imaging 2
• 76% response rate with median time to response of 12 weeks, but 24% recurrence rate (median 19 months) 5
• Close surveillance is essential, and definitive surgery remains necessary if disease recurs or fertility goals are met 1, 5

For medically inoperable patients:

• External beam radiotherapy and/or brachytherapy can be considered 3
• This is reserved for patients with significant comorbidities (obesity, cardiac disease, diabetes) precluding surgery 3

Common Pitfalls to Avoid

• Do not perform lymphadenectomy in this low-risk setting—it increases morbidity without survival benefit 1, 2
• Do not prescribe adjuvant radiation for low-risk disease—it reduces local recurrence but does not improve survival and adds toxicity 3
• Do not use progestational agents as adjuvant therapy—they are ineffective in low-stage disease 3, 1
• Do not order routine imaging during surveillance—it is not cost-effective and does not improve outcomes 4