Pathologic characteristics of second breast cancers after breast conservation for ductal carcinoma in situ

Comparison of the association of mammographic density and clinical factors with ductal carcinoma in situ versus invasive ductal breast cancer in Korean women

BACKGROUND

In spite of the increasing incidence of in situ breast cancer, the information about the risk factors of in situ breast cancer (DCIS) is scarce as compared to the information available for invasive ductal breast cancer (IDC), with inconsistent findings regarding the difference in risk factors between DCIS and IDC.

METHODS

We enrolled 472 women with IDC and 90 women with DCIS and 1088 controls matching for age and menopausal status. Information on risk factors was collected through self-administered questionnaire. Percent mammographic dense area (PDA), absolute mammographic dense area (ADA), and nondense area were assessed using a computer-assisted thresholding technique. Odds ratio (OR) and 95% confidence intervals (CI) were estimated by conditional logistic regression model with adjustment for covariates.

RESULTS

Later age at menarche and regular physical exercise were associated with decreased risk of IDC, whereas alcohol consumption, previous benign breast disease, and family history of breast cancer were associated with increased risk of IDC. For DCIS, previous benign breast disease and alcohol consumption were associated with the increased risk, and regular physical exercise was associated with decreased risk. Increase of ADA by 1-quartile level and PDA increase by 10% were associated with 1.10 (95% CI: 1.01, 1.21) and 1.10 (95% CI: 1.01, 1.19) times greater risk of IDC, respectively. The increase of ADA by 1-quartile level and PDA increase by 10% were associated with 1.17 (95% CI: 0.91, 1.50) times and 1.11 (95% CI:0.90,1.37) times greater risk of DCIS, respectively, but the associations were not statistically significant. There was no significant difference in the association with risk factors and mammographic density measures between IDC and DCIS (P > 0.1).

CONCLUSIONS

Differential associations of DCIS with mammographic density and risk factors as compared with the associations of IDC were not evident. This finding suggests that IDC and DCIS develop through the shared causal pathways.

Clinical-pathological features and treatment modalities associated with recurrence in DCIS and micro-invasive carcinoma: Who to treat more and who to treat less

The primary aim in the management of DCIS is the prevention of recurrence and contralateral tumor. Risk factors for DCIS recurrence and appropriate treatments are still widely debated. Adjuvant therapies after surgical resection reduce recurrences and contralateral disease, but these treatments have significant financial costs, side effects and there is a group of low-risk patients who would not gain additional benefit. The aim of our analysis was to identify clinical-pathological features and treatment modalities associated with recurrence in DCIS and microinvasive carcinoma. In the Thomas Jefferson University Cancer Registry of Philadelphia, we identified 865 patients with DCIS or micro-invasive carcinoma treated between 2003 and 2013. Associations between recurrence and demographic factors (age at diagnosis, ethnicity), biological features (ER, PR and HER2) and treatment modalities (surgery, radiotherapy and endocrine treatment) were assessed. Our single institution register-based study showed that distribution of age at diagnosis and biological features did not significantly differ among ethnic groups. Younger women and micro-invasive carcinoma patients were more likely to undergo mastectomy, while African Americans were more likely to take endocrine therapy and undergo radiotherapy. In our sample only ER/PR negative DCIS were associated with significantly higher recurrence rate. Moreover, we reported a high rate of HER2 positive recurrences, suggesting that expression of this oncogene may represent a potential biomarker for DCIS at high risk of recurrence. To better define the molecular profile of the subgroup at worse prognosis might help to identify biomarkers predictive of recurrence or second tumors, identifying patients candidates for more appropriate treatments.

Patient Prognostic Score and Associations With Survival Improvement Offered by Radiotherapy After Breast-Conserving Surgery for Ductal Carcinoma In Situ: A Population-Based Longitudinal Cohort Study

PURPOSE

Radiotherapy (RT) after breast-conserving surgery (BCS) is a standard treatment option for the management of ductal carcinoma in situ (DCIS). We sought to determine the survival benefit of RT after BCS on the basis of risk factors for local recurrence.

PATIENTS AND METHODS

A retrospective longitudinal cohort study was performed to identify patients with DCIS diagnosed between 1988 and 2007 and treated with BCS by using SEER data. Patients were divided into the following two groups: BCS+RT (RT group) and BCS alone (non-RT group). We used a patient prognostic scoring model to stratify patients on the basis of risk of local recurrence. We performed a Cox proportional hazards model with propensity score weighting to evaluate breast cancer mortality between the two groups.

RESULTS

We identified 32,144 eligible patients with DCIS, 20,329 (63%) in the RT group and 11,815 (37%) in the non-RT group. Overall, 304 breast cancer-specific deaths occurred over a median follow-up of 96 months, with a cumulative incidence of breast cancer mortality at 10 years in the weighted cohorts of 1.8% (RT group) and 2.1% (non-RT group; hazard ratio, 0.73; 95% CI, 0.62 to 0.88). Significant improvements in survival in the RT group compared with the non-RT group were only observed in patients with higher nuclear grade, younger age, and larger tumor size. The magnitude of the survival difference with RT was significantly correlated with prognostic score (P < .001).

CONCLUSION

In this population-based study, the patient prognostic score for DCIS is associated with the magnitude of improvement in survival offered by RT after BCS, suggesting that decisions for RT could be tailored on the basis of patient factors, tumor biology, and the prognostic score.

Genetic predisposition to ductal carcinoma in situ of the breast

BACKGROUND

Ductal carcinoma in situ (DCIS) is a non-invasive form of breast cancer. It is often associated with invasive ductal carcinoma (IDC), and is considered to be a non-obligate precursor of IDC. It is not clear to what extent these two forms of cancer share low-risk susceptibility loci, or whether there are differences in the strength of association for shared loci.

METHODS

To identify genetic polymorphisms that predispose to DCIS, we pooled data from 38 studies comprising 5,067 cases of DCIS, 24,584 cases of IDC and 37,467 controls, all genotyped using the iCOGS chip.

RESULTS

Most (67 %) of the 76 known breast cancer predisposition loci showed an association with DCIS in the same direction as previously reported for invasive breast cancer. Case-only analysis showed no evidence for differences between associations for IDC and DCIS after considering multiple testing. Analysis by estrogen receptor (ER) status confirmed that loci associated with ER positive IDC were also associated with ER positive DCIS. Analysis of DCIS by grade suggested that two independent SNPs at 11q13.3 near CCND1 were specific to low/intermediate grade DCIS (rs75915166, rs554219). These associations with grade remained after adjusting for ER status and were also found in IDC. We found no novel DCIS-specific loci at a genome wide significance level of P < 5.0x10(-8).

CONCLUSION

In conclusion, this study provides the strongest evidence to date of a shared genetic susceptibility for IDC and DCIS. Studies with larger numbers of DCIS are needed to determine if IDC or DCIS specific loci exist.

Characteristics of second breast events among women treated with breast-conserving surgery for DCIS in the community

We examined the clinical/pathologic features of ipsilateral second breast cancers (IP-SBCs) following breast-conserving surgery (BCS) for DCIS among community-treated patients and ascertained the degree of correlation between the features of index DCIS and IP-SBC events. From a Cancer Research Network cohort of DCIS patients diagnosed 1990-2001 and treated with BCS, we identified women who subsequently developed an ipsilateral DCIS or invasive breast cancer. All index DCIS tumors underwent expert pathology review. Pathologic characteristics of IP-SBCs were abstracted from available medical records. Logistic regression was used to examine associations between pathologic characteristics and identify factors associated with invasive versus non-invasive IP-SBC. Of 1969 DCIS patients, 182 developed an IP-SBC within a median of 38 months (range 6-160). IP-SBCs were slightly more commonly non-invasive (53 %) versus invasive (47 %). Of invasive IP-SBCs, 31 % were high grade, 67 % were <20 mm, 74 % were estrogen receptor positive, 7 % were HER2 positive, and 16 % were node positive. Of non-invasive IP-SBCs, 33 % were high grade. Comparing index DCIS and IP-SBC specimens, there was moderate-high correlation for HR status and grade. Among patients with IP-SBCs, those who were younger and whose index DCIS tumors were HR negative had shorter intervals (within 3 years) between index and IP-SBC diagnoses. No index DCIS feature was statistically significantly associated with an IP-SBC that was invasive versus non-invasive. Understanding the characteristics of SBCs and identifying correlations between these and index DCIS events could influence treatment choices for DCIS, and may help patients and providers develop treatment paradigms for SBCs.

Molecular Markers as Prognostic Factors in DCIS and Small Invasive Breast Cancers

Ductal carcinoma in situ (DCIS) accounts for up to half of screen-detected breast cancers and thus constitutes a major public health problem. Despite effective current treatment many patients with DCIS are either over- or undertreated because of the paucity of precise models to predict recurrence or progression. The combination of clinical and molecular factors as already applied for invasive disease may help to build such models also for DCIS. We compared 53 DCIS (36.6 %) and 92 (63.4 %) invasive breast cancer cases and found no significant differences in age, receptor status of ER, PR, and HER2, and the use of radiotherapy. Interestingly, the proportion of disseminated tumor cells (DTC) did also not significantly differ between DCIS and invasive cases (p = 0.57). A negative PR status was associated with the detection of DTCs (p = 0.026). We then compared relationships of clinical parameters and biomarkers with patients' prognosis in 43 DCIS and 40 small invasive tumors ≤ 5 mm (T1a). ER negativity was associated with shorter relapse free survival in the complete cohort (p = 0.004) and showed a trend in both subgroups (p = 0.053 for DCIS and p = 0.046 for T1a, respectively). In conclusion, we found markedly similar properties of both DCIS and small invasive breast cancers with respect to the distribution of several parameters as well as to the prognostic value of biomarkers. DCIS with a luminal phenotype seem to be characterized by a favourable prognosis.