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Breast cancer

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Risk of breast cancer recurrence and adjuvant therapy

Adjuvant therapy is additional treatment that may be given after breast cancer surgery to reduce the risk of the cancer coming back (recurring).

For women who have breast cancer that has not spread to the lymph nodes (node-negative breast cancer), the decision to offer adjuvant therapy is based on her level of risk of recurrence. The benefit of using adjuvant therapy is balanced against the risks associated with receiving treatment.

Levels of risk

There are 3 levels of risk for breast cancer recurrence. These levels are based on the known prognostic factors for breast cancer. Generally, women who have breast cancer with high-risk characteristics have the greatest chance that their breast cancer will recur.

Risk of breast cancer recurrence and adjuvant therapy
Level of riskBreast cancer characteristicsAdjuvant therapies that may be offered

Low – has all the characteristics

The tumour is smaller than 1 cm in diameter.

There is no cancer in the lymph nodes.

The tumour is hormone receptor positive.

The cancer is low grade (grade 1).

The cancer has not spread to the lymph vesselslymph vesselsA tube through which lymph fluid travels in the body. or blood vessels in the breast tissue.

Radiation therapy

Hormonal therapy

Moderate (intermediate) – has all the characteristics

The tumour is 1–2 cm in diameter.

There is no cancer in the lymph nodes.

The tumour is hormone receptor positive.

The cancer is grade 1 or 2.

The cancer has not spread to the lymph vessels or blood vessels in the breast tissue.

Radiation therapy

Hormonal therapy

Chemotherapy

High – has at least 1 characteristic

The tumour is larger than 2 cm in diameter.

The tumour is hormone receptor negative.

The tumour is high grade (grade 2 or 3).

The tumour has invaded the lymph vessels or the blood vessels.

The tumour has spread into the chest wall or the skin of the breast.

The cancer is inflammatory breast cancer.

The tumour is HER2 positive.

Radiation therapy

Chemotherapy

Biological therapy

Hormonal therapy

Women who have cancer in the lymph nodes (node-positive breast cancer) will always be offered chemotherapy.

Types of adjuvant therapy

The types of adjuvant therapy that may be used after breast cancer surgery are:

  • radiation therapy
    • Radiation therapy is used to reduce the risk of a local recurrence (cancer that comes back in the same area as the original tumour) after breast-conserving surgery.
    • It may also be given after mastectomy if there is a high risk for recurrence.
  • chemotherapy
    • Chemotherapy is given to reduce the risk of breast cancer spreading to or recurring in another part of the body (metastatic breast cancer).
  • hormonal therapy
  • biological therapy
    • Biological therapy is used to reduce the risk of metastatic breast cancer in women with HER2-positive breast cancer.

These treatments may be used alone or in combination to reduce the chance of breast cancer recurring and to improve survival. Adjuvant therapy is often started 4–12 weeks after breast cancer surgery.

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