Deciding what steps to take after surgery

A lumpectomy alone plan is less common than lumpectomy plus radiation. To see how clinical consensus guidelines from NCCN and ASCO treat the option of lumpectomy alone, see my post from yesterday in your other thread:

https://community.breastcancer.org/forum/68/topics/854451?page=1#post_4952312

The ASCO guideline linked in that thread commented on excision alone:

ASCO (Morrow, 2016): http://ascopubs.org/doi/pdf/10.1200/JCO.2016.68.3573

"Treatment With Excision Alone

Treatment with excision alone, regardless of margin width, is associated with substantially higher rates of IBTR [ipsilateral breast tumor recurrence] than treatment with excision and WBRT [whole-breast irradiation], even in predefined low-risk patients. The optimal margin width for treatment with excision alone is unknown, but should be at least 2 mm. Some evidence suggests lower rates of IBTR with margin widths wider than 2 mm.

The EBCTCG DCIS meta-analysis showed that the 10-year IBTR rate for patients treated with excision alone was higher than with excision and WBRT, both for those with negative margins (26.0% vs 12.0%, P < .00001) and positive margins (48.3% vs 24.2%; P = .00004). [1] The same proportional benefit for WBRT was seen in women treated with local excision and those having large sector resections. In the Radiation Therapy Oncology Group (RTOG) 9804 trial where patients with small, mammographically detected low-to-intermediate grade DCIS and margins ≥ 3 mm were randomized to excision alone or excision plus WBRT, 7-year IBTR rates were 6.7% and 0.9% (P = .0003), respectively. [4] The prospective, multi-institutional Eastern Cooperative Oncology Group (ECOG) E5194 study of patients with low-risk DCIS treated with excision alone (negative margin width ≥ 3 mm) reported 12-year rates of IBTR of 14.4% for nonhigh grade DCIS ≤ 2.5 cm in size and 24.6% for high-grade DCIS ≤ 1 cm in size. However, IBTR rates did not differ significantly for margins < 5 mm, 5-9 mm, or ≥ 10 mm (P = .85).[23] A prospective single-arm study of patients with mammographically detected DCIS ≤ 2.5 cm in size reported a 10-year IBTR rate of 15.6% [24] despite requiring margins of ≥ 1 cm. [4] In contrast, Van Zee et al found in 1266 patients treated with excision alone that 10-year IBTR rates were 16% for margins > 10 mm, and increased to 23% for margins between 2.1 and 10 mm, 27% for > 0-2 mm, and 41% for positive margins. After adjustment for multiple factors, margin width was a more highly significant predictor of IBTR (P < .0001). [22] The MP felt that, overall, the heterogeneity of the evidence between the above-reported studies did not allow for a definitive recommendation for margin widths greater than 2 mm in patients foregoing RT."

While there are retrospective, observational studies in this area, such studies have significant limitations. Here is a link to the 10- and 12-year outcomes from the prospective ECOG-ACRIN 5194 trial mentioned in the above passage, which assessed recurrence with excision alone:

Solin (2015): "Surgical Excision Without Radiation for Ductal Carcinoma in Situ of the Breast: 12-Year Results From the ECOG-ACRIN E5194 Study"

http://ascopubs.org/doi/pdf/10.1200/JCO.2015.60.8588

This led to some discussion:

Shah (2016): "Radiation Therapy and the Evolving Definition of Low Risk in Ductal Carcinoma in Situ"

http://ascopubs.org/doi/full/10.1200/jco.2015.64.9202

Authors' Reply to Shah (2016):

http://ascopubs.org/doi/abs/10.1200/JCO.2016.66.4714

As you note, a personalized risk/benefit analysis will be undertaken on the basis of the combined pathology results from all surgeries and biopsies. In addition to young age being a risk factor (per my reply in your other thread), the results of the surgical pathology may significantly impact understanding of your recurrence risk profile (e.g., margin size, grade, extent of DCIS), or even presence of invasive disease seen in about 20% of cases overall, which may render moot consideration of foregoing radiation for some patients.

BarredOwl

Melrose7, I am 46 had dcis diagnosed In October had lumpectomy and 15 sessions of radiation it never even occurred to me not to do radiation I want everything thrown at this I started tamixofen in March was dreading it I'm ok so far k never want to revisit the last 6 months again I was told by oncologist that I was to have radiation and it was my decision about tamixofen I decided I'd nothing to loose trying it so I decided I'd take it for 6 months no matter what side effects were so we'll see how it goes