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HER2-positive breast cancer, stage II-III

HER2-positive breast cancer →

Chemotherapy with two HER2 antibodies for about four months before surgery; what the surgeon finds decides the next year of anti-HER2 treatment (antibodies alone, or the ADC T-DM1 if cancer remained).

03691 yr15Months from diagnosis · solid bar = shortest typical duration, hatched = up to the longest · arrow = continues for yearsPhaseDiagnosis and stagingDiagnosis and tests · 2-4 wkNeoadjuvant chemotherapy + trastuzuma…Before surgery · 18 wkSurgerySurgery and recovery · 3-6 wkAdjuvant anti-HER2 therapyAfter surgery · 34-42 wkRadiotherapyRadiotherapy · 3-6 wk · alongsideEndocrine therapy (if also HR-positiv…Systemic therapy · yearsSurveillanceSurveillance · yearsWas there a pathological complete response?decision 1Diagnosis and testsBefore surgerySurgery and recoveryAfter surgeryRadiotherapySystemic therapySurveillance
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Typical sequence for stage II-III (operable) disease; durations are protocol values (cycle counts and lengths, fraction schedules, guideline follow-up intervals), not averages of real patients. Your team's plan will differ in detail.

Phase by phase

  1. 1. Diagnosis and staging
    weeks 0-4

    Core biopsy with HER2 by IHC and in-situ hybridisation; imaging; echocardiogram before anti-HER2 therapy.

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  2. 2. Neoadjuvant chemotherapy + trastuzumab + pertuzumab
    weeks 2-20

    Six 3-week cycles of docetaxel and carboplatin with trastuzumab and pertuzumab (TCHP).

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  3. 3. Surgery
    weeks 20-26

    Breast surgery with sentinel node biopsy; the pathology report shows whether invasive cancer remains.

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    Decision: Was there a pathological complete response?
    • pCR: finish the year with trastuzumab and pertuzumab
    • Residual invasive disease: switch to T-DM1 for 14 cycles (KATHERINE)
  4. 4. Adjuvant anti-HER2 therapy
    weeks 23-65

    pCR: trastuzumab and pertuzumab to complete one year of antibody therapy. Residual disease: trastuzumab emtansine (T-DM1) for 14 cycles (KATHERINE), about 42 weeks.

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  5. 5. Radiotherapy
    weeks 23-29 (alongside the previous phase)

    Given during antibody therapy after breast conservation or node-positive mastectomy.

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  6. 6. Endocrine therapy (if also HR-positive)
    from week 57, continues for years

    Tamoxifen or an aromatase inhibitor for 5-10 years when the tumour is also hormone receptor positive.

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  7. 7. Surveillance
    from week 317, continues for years

    Clinic visits every 3-6 months for 3 years then yearly; annual mammography; cardiac monitoring during antibody therapy.

    Source

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