Dr HB LoIntegrative GP · drhblo.com

Treatment decision · breast cancer

Radiotherapy after your lumpectomy?

You've had breast-conserving surgery and now there's an offer of radiotherapy on the table. Tell me where you're up to, and I'll hand you the real numbers and the exact questions — ready to take to your radiation oncologist.

Where are you up to?

Or tap an example to start:

A bit more (optional) Skip — these just sharpen the questions
Your age band
On hormone (endocrine) tablets?
What matters most to you right now?

This tool helps you prepare — it can't tell if something is serious. If you're worried it might be urgent, call 000 or your GP now.

Dr HB Lo · Integrative GP · drhblo.com/tools/radiotherapy-after-lumpectomy · generated . General information to help you prepare — not medical advice, not a recommendation for or against any treatment, and not an emergency service.

Radiotherapy is very good at one thing: it lowers the chance the cancer comes back in that breast — from roughly 1 in 10 down to about 1 in 100 over ten years. The separate question — the one worth asking out loud — is whether, for someone in your situation, it changes how long you live. For a defined low-risk group, that hasn't been shown. Decide which of those matters most to you before you walk in.

Two different questions

General population figures from the research below — not your personal numbers. Only your radiation oncologist can tell you how they apply to your case.

Radiotherapy after a lumpectomy does two different jobs — and they don't always point the same way.
Comes back in the breast
(local recurrence, 10 years)		 How long you live
(overall survival)
With radiotherapy: about 1 in 100
Without: about 1 in 10 → radiotherapy clearly reduces this 		In the low-risk group studied: no difference shown
(PRIME II, 10 years) → this is the question to ask about YOUR case

100 women like the low-risk group studied, 10 years on, who skipped radiotherapy:

came back in the breast (about 10)    no return in the breast (about 90)

Without radiotherapy, about 90 of 100 still had no return in the breast at 10 years. Radiotherapy lifts that to about 99 of 100. (PRIME II low-risk cohort — 10-year data.)

Across all women (not just the low-risk group), the benefit is larger — radiotherapy roughly halves recurrence and modestly improves survival (EBCTCG). The "low-risk" group where omission is even on the table is narrow — only your radiation oncologist can tell you whether your actual pathology fits it.

The honest part

Two honest things this tool won't dress up. One: radiotherapy genuinely works — for many women, especially younger women or those with higher-risk features, the benefit in preventing recurrence (and, across the whole group, survival) is real and the standard recommendation. The "low-risk" group where omission is even on the table is narrow, and only your radiation oncologist can tell you if your actual pathology fits it. Two: radiotherapy is not free of cost — it's 3 to 6 weeks of daily visits, and it has side-effects (tiredness, skin reaction, sometimes longer-term changes to the breast or, rarely, heart and lung). Neither of these is a reason on its own. They're the trade-off you're entitled to weigh out loud.

Radiotherapy is almost always recommended after breast-conserving surgery (Cancer Australia).

The questions to take in

    This is the general version. The full breast-cancer treatment decisions kit walks you through radiotherapy, the hormone-tablet decision, and the reconstruction questions — with the real numbers filled in for your situation, and a worksheet to take to every appointment.

    Facing the whole decision? Try the BRAN question generator for the four questions that cut through →
    What do these numbers mean? See the NNT visualiser →  ·  Read the breast-cancer decisions explainer →

    Where these figures come from

    The "1 in 10 → 1 in 100" figure is the PRIME II low-risk cohort (10-year local recurrence 9.8% without radiotherapy vs 0.9% with, with no difference in overall survival). The broader EBCTCG figure (radiotherapy roughly halves recurrence; in node-negative disease 10-year first-recurrence fell from about 31% to about 16%) describes all women, not just the low-risk group. AU primary-source figures verified 2026-06-09 via WebSearch — Cancer Australia and RANZCR Targeting Cancer pages confirmed live. Clinical sign-off of figures and questions still pending before go-live.