Margins and Reexcisions

Margins and Reexcisions

This invasive ductal carcinoma image is closest to the yellow inked margin image. A perpendicular margin has been taken. The distance of the invasive carcinoma from the margin can be determined image.

An en face margin is shaved from the surface of a specimen, such as this section of the yellow margin. Although more tissue is sampled, the distance of carcinoma from the margin cannot be measured.


Margins and Local Recurrence Rates

  • Carcinoma present at inked margin (“positive” margin) correlates with higher likelihood of residual disease in the breast

    • Carcinoma close to margins also increases likelihood of residual disease, but magnitude of risk is dependent on type of cancer (invasive or in situ), distance from margin, and extent

  • Residual carcinoma in the breast is associated with increased risk of local recurrence

  • Minimizing risk of local recurrence is important goal

    • Can improve survival for patients whose initial carcinoma is likely curable (carcinoma in situ and small node-negative invasive carcinomas)

    • Reduces need for additional surgery and treatment

    • Reduces possibility of uncontrolled local disease in skin and chest wall (“carcinoma en cuirasse”)

    • Recurrence is often very psychologically difficult for patients

      • Often mastectomy is required for treatment as radiation cannot be delivered to chest 2nd time

  • Margins for palpable invasive carcinomas are generally negative

    • Surgeon palpates the cancer and excises rim of grossly normal tissue

    • Apparently positive margin on microscopic examination may be due to ink leakage or inadvertent incision into carcinoma

    • Generally several mm of cauterized tissue within biopsy cavity

      • Residual carcinoma at edge of biopsy site will not be viable

    • Therefore, focally positive margin for invasive cancer usually does not correlate with residual invasive carcinoma in the patient

  • Margins for nonpalpable invasive carcinomas (due to small size or diffusely invasive pattern) may be positive

    • Surgeon cannot palpate the cancer and, therefore, must make educated guess as to how much tissue to remove

    • If carcinoma is transected, it will be present at margin over broad front

      • Cautery artifact on carcinoma supports that margin is a true surgical margin

      • Extensive residual carcinoma may be present in breast

  • Margins are often positive or close for DCIS

    • DCIS is rarely grossly evident

    • Extent of DCIS cannot be determined with certainty by clinical examination or imaging

    • Surgeon cannot definitively know how much tissue to remove

    • Margins can only be evaluated with certainty microscopically on permanent sections

Prediction of Residual Carcinoma

  • Even under best conditions, likelihood of residual carcinoma in breast can only be estimated

  • Presence of cancer at margins does not predict residual cancer with certainty

    • There may not be breast tissue beyond edge of specimen

      • Particularly relevant for margins adjacent to skin and pectoralis muscle

    • Often several mm of cauterized tissue in biopsy cavity in patient

      • Cautery may destroy small amounts of residual invasive carcinoma

    • Margins may be falsely positive due to ink leakage into cracks or specimen fragmentation

    • Can be gaps between areas of involvement by DCIS

      • Duct at margin can appear free of DCIS, but DCIS can be present further along in duct

    • Margins can be falsely negative if areas of involvement are not sampled or if areas are too small to be present within the width of the section

Risk Factors for Local Recurrence

  • Approximately 10% of patients will have local recurrence at 10 years

  • Risk factors for recurrence include

    • Young patient age

    • Poorly differentiated carcinomas

    • Positive margins

    • Extensive intraductal component (EIC) with DCIS located away from invasive carcinoma

    • Extensive lymph-vascular invasion

  • Subtypes of breast cancer have different local recurrence rates at 5 years

    • Luminal A (ER or PR positive, HER2 negative): 0.8%

    • Luminal B (ER or PR positive, HER2 positive): 1.5%

    • HER2 (ER and PR negative, HER2 positive): 8.4%

    • Triple negative (basal-like) (ER, PR, and HER2 negative): 7.1%

  • Growth rate of hormone-positive carcinomas can be inhibited by hormonal therapy over many years

  • Patients with HER2-positive carcinomas are now being treated with HER2-targeted therapy over many years

    • Treatment reduces likelihood of local recurrence

  • Targeted therapy for triple negative carcinomas is not yet available


En Face (Shave)

Jul 6, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Margins and Reexcisions

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