Benefits of Radiation therapy following Lumpectomy and PCR.

Phily

I’ve created a new post as for some reason my replies to the earlier posts wouldn’t attach. Thanks RocDocVic. From GPT:

What are the chances of recurrence of early stage breast cancer treated with TCHP and radiation therapy vs no radiation therapy, where the patient had a lumpectomy and achieved a pathological complete response (PCR) to neoadjuvant therapy?

For a patient with early-stage breast cancer who has undergone a lumpectomy and achieved a pathological complete response (pCR) to neoadjuvant therapy (TCHP), the chances of recurrence are influenced by several factors, including whether radiation therapy is part of the treatment plan. Achieving pCR is a very favorable prognostic factor and generally indicates a lower risk of recurrence.

With Radiation Therapy

• Local Control and Recurrence: Radiation therapy is typically recommended following lumpectomy to address any microscopic residual disease and to decrease the risk of local recurrence. Studies have shown that even patients with pCR benefit from radiation therapy in terms of reducing local recurrence rates. For such patients, the local recurrence rate can be very low, often less than 5% over 10 years.
• Overall Benefit: The combination of achieving pCR and receiving radiation therapy provides excellent local control and contributes to the overall survival benefit. This integrated approach ensures that any potential residual cancer cells are eradicated, maintaining the effectiveness of the pCR.

Without Radiation Therapy

• Local Recurrence Risk: Omitting radiation therapy increases the risk of local recurrence, even in patients who have achieved pCR. While pCR significantly reduces the risk of recurrence, it does not entirely eliminate the possibility of local recurrence. In such cases, local recurrence rates can be higher, potentially ranging from 10-20% over 10 years.
• Considerations: The decision to omit radiation therapy might be considered in specific cases based on patient preference, comorbidities, or other factors. However, it is generally less common to omit radiation therapy in standard clinical practice for patients who have had a lumpectomy.

Clinical Evidence and Guidelines

• National Comprehensive Cancer Network (NCCN) Guidelines: These guidelines typically recommend radiation therapy after lumpectomy for early-stage breast cancer, regardless of the pCR status, to ensure maximum local control.
• Research Studies: Clinical studies have consistently shown that the addition of radiation therapy after lumpectomy reduces the risk of local recurrence, even in patients who achieve pCR with neoadjuvant therapy. For example, a study published in JAMA Oncology indicated that patients who achieved pCR but did not receive radiation therapy had higher rates of local recurrence compared to those who did receive radiation therapy.

Summary

• With Radiation Therapy: The chances of local recurrence are very low, often less than 5% over 10 years, given the excellent response to TCHP and pCR.
• Without Radiation Therapy: The risk of local recurrence is higher, potentially in the range of 10-20% over 10 years, even with pCR.

Ultimately, the decision to include radiation therapy should be made in consultation with the patient’s oncology team, considering the individual circumstances, potential benefits, and risks. The strong evidence supports the use of radiation therapy to maximize local control and reduce recurrence risk.