Heterogeneity of invasive ductal carcinoma: proposal for a hypothetical classification

Isogenic Mammary Models of Intraductal Carcinoma Reveal Progression to Invasiveness in the Absence of a Non-Obligatory In Situ Stage

In breast cancer, progression to invasive ductal carcinoma (IDC) involves interactions between immune, myoepithelial, and tumor cells. Development of IDC can proceed through ductal carcinoma in situ (DCIS), a non-obligate, non-invasive stage, or IDC can develop without evidence of DCIS and these cases associate with poorer prognosis. Tractable, immune-competent mouse models are needed to help delineate distinct mechanisms of local tumor cell invasion and prognostic implications. To address these gaps, we delivered murine mammary carcinoma cell lines directly into the main mammary lactiferous duct of immune-competent mice. Using two strains of immune-competent mice (BALB/c, C57BL/6), one immune-compromised (severe combined immunodeficiency; SCID) C57BL/6 strain, and six different murine mammary cancer cell lines (D2.OR, D2A1, 4T1, EMT6, EO771, Py230), we found early loss of ductal myoepithelial cell differentiation markers p63, α-smooth muscle actin, and calponin, and rapid formation of IDC in the absence of DCIS. Rapid IDC formation also occurred in the absence of adaptive immunity. Combined, these studies demonstrate that loss of myoepithelial barrier function does not require an intact immune system, and suggest that these isogenic murine models may prove a useful tool to study IDC in the absence of a non-obligatory DCIS stage-an under-investigated subset of poor prognostic human breast cancer.

Is there a difference in FDG PET findings of invasive ductal carcinoma of the breast with and without coexisting DCIS?

OBJECTIVES

Studies have reported that invasive ductal carcinoma (IDC) with coexisting ductal carcinoma in situ (DCIS) show lower metastatic potential and recurrence and better overall survival than pure IDC. In this study, we assessed F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) images of patients with newly diagnosed IDC to determine if there is any difference in PET findings in IDC-DCIS and pure IDC cases.

METHODS

FDG PET/CT images of patients with newly diagnosed IDC of the breast who subsequently underwent breast surgery and had histopathology result in our records were further evaluated. Tumor grade, pathological staging, and presence of DCIS were noted from the histopathology results. Standardized uptake value (SUV) of the primary tumor (SUVmax and SULmax), other hypermetabolic foci in the breast, and ipsilateral normal breast were measured. Presence of axillary and distant metastases was noted.

RESULTS

Fifty seven (57) patients with IDC were included. Coexisting DCIS was present in 44 (IDC-DCIS) and not present in 13 (pure IDC) cases. Per histopathology, the primary tumor was unifocal in 33 IDC-DCIS (75%) and 12 pure IDC (92.3%) cases, and multifocal in 11 IDC-DCIS cases (25%), and 1 pure IDC case (7.7%). FDG uptake was multifocal in 20 IDC-DCIS cases (45.5%) and 1 pure IDC case (7.7%), and unifocal in 24 IDC-DCIS (54.5%), and 12 pure IDC (92.3%) cases. There was no significant difference in patient age, size of the primary tumor, SUVmax and SULmax of the primary tumor and SUVmax of the normal breast in IDC-DCIS and pure IDC cases (p>0.05). Pathology showed axillary metastasis in all 13 pure IDC (100%), and 27 IDC-DCIS (61.4%) cases. PET showed axillary uptake in 25 IDC-DCIS (56.8%), and 8 pure IDC (61.5%) cases, and abnormal/questionable distant uptake in 12 IDC-DCIS cases and 1 pure IDC case.

CONCLUSION

In our preliminary findings, multifocal breast FDG uptake and multifocal tumor appear to be more common in IDC-DCIS than pure IDC. There is no significant difference in SUV and size of the primary tumor in IDC-DCIS and pure IDC cases. Axillary metastases appear to be more common in pure IDC than IDC-DCIS cases.

The prognostic significance of co-existence ductal carcinoma in situ in invasive ductal breast cancer: a large population-based study and a matched case-control analysis

Background

To evaluate the prognostic significance of co-existence ductal carcinoma in situ (DCIS) in invasive ductal breast cancer (IDC) compared with pure IDC.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was searched to identify unilateral IDC cases between 2004 and 2015, which were grouped into pure IDC and IDC with DCIS component (IDC-DCIS). Comparisons of the distribution of clinical-pathological characteristics the two groups were performed using Pearson's chi-square. Breast cancer-specific survival (BCSS) and overall survival (OS) were estimated using the Kaplan-Meier method and compared across RS groups using the log-rank statistic. Cox models were fitted to assess the factors independently associated with survival. A 1:1 matched case-control analysis was conducted with each clinical-pathological characteristic matched completely.

Results

A total of 98,097 pure IDC cases (39.6%) and 149,477 IDC-DCIS cases (60.4%) were enrolled. IDC-DCIS patients were presented with less aggressive characteristics such as lower proportion of histologic grade III (34.2% vs. 42.2%, P<0.001), ER negative (16.8% vs. 26.1%, P<0.001) and PR negative (26.5% vs. 35.7%, P<0.001) disease and higher proportion of T1 cases (68.7% vs. 58.2%, P<0.001) compared with pure IDC patients. Co-existence DCIS was an independent prognostic factor for BCSS and OS in the whole cohort. According to the multivariate analysis, it was an independent favorable prognostic factor among ER positive cases, but an independent negative prognostic factor among ER negative cases based on the matched cohort.

Conclusions

Co-existence DCIS showed quite different prognostic significance among ER positive and negative disease.

Prognostic value of ductal carcinoma in situ component in invasive ductal carcinoma of the breast: a Surveillance, Epidemiology, and End Results database analysis

Background

The prognostic implication of concomitant ductal carcinoma in situ (DCIS) in invasive ductal carcinoma (IDC) remains controversial. Our objective was to investigate whether concomitant DCIS affects survival outcomes in patients with IDC.

Materials and methods

Patients with nonmetastatic breast cancer who underwent surgery in 2010–2014 were included from the Surveillance, Epidemiology, and End Results program. Statistical analyses were conducted using χ² test, linear-by-linear association, one-way analysis of variance, Kaplan–Meier method, Cox proportional hazards regression model, and propensity score matching (PSM).

Results

A total of 61,745 patients were identified, including 44,630 (72.3%), 13,559 (22.0%), and 3,556 (5.7%) patients with no DCIS component reported (No-DCIS), DCIS <25% (L-DCIS), and ≥25% (H-DCIS), respectively. Patients with H-DCIS were more likely to be younger (p<0.001), have smaller tumors (p<0.001), good/moderate differentiation (p<0.001), human epidermal growth factor receptor 2–positive disease (p<0.001), receive mastectomy (p<0.001), and not receive radiotherapy (p<0.001) and chemotherapy (p<0.001). The median follow-up was 27 months, and the 2-year breast cancer-specific survival (BCSS) in patients with No-DCIS, L-DCIS, and H-DCIS was 97.3%, 98.0%, and 98.5%, respectively (p<0.001). Before PSM, H-DCIS was an independent favorable prognostic factor for BCSS; patients with H-DCIS had better BCSS compared to patients with No-DCIS (hazard ratio [HR] 0.674, 95% CI: 0.528–0.861, p=0.002), while the BCSS between No-DCIS and L-DCIS was similar (HR 0.944, 95% CI: 0.840–1.061, p=0.334). However, this survival advantage disappeared after PSM; there was significantly different BCSS between patients with No-DCIS and H-DCIS (HR 0.923, 95% CI: 0.653–1.304, p=0.650). H-DCIS was not associated with BCSS as compared to No-DCIS in the breast-conserving surgery (p=0.295) and mastectomy (p=0.793) groups.

Conclusion

In breast cancer, patients with H-DCIS have unique clinicopathologic features compared to patients with No-DCIS. Before PSM, H-DCIS was associated with favorable BCSS as compared to No-DCIS. However, the survival advantage disappeared after PSM.

Grade of ductal carcinoma in situ accompanying infiltrating ductal carcinoma as an independent prognostic factor

BACKGROUND

Several studies about the relationship between IDC and DCIS have been reported, but no consensus has been reached regarding clinical characteristics and prognostic value.

PATIENTS AND METHODS

We reviewed the medical records of patients who underwent surgery for IDC between 2006 and 2008. DCIS adjacent to IDC was pathologically classified as either high-grade DCIS or non-high-grade DCIS.

RESULTS

Among 1751 IDC patients within the study period, 1384 patients (79.0%) had concomitant DCIS. There was no survival difference between patients with pure IDC and those with IDC and concomitant DCIS. However, patients with high-grade DCIS had worse survival than did patients with non-high-grade DCIS or pure IDC (5-year recurrence-free survival rates for IDC with non-high-grade DCIS, pure IDC without DCIS, and IDC with high-grade DCIS were 97%, 93%, and 86%, respectively; P = .001). This tendency was maintained regardless of estrogen receptor status or histologic grade of IDC. In a Cox regression model, patients with IDC and accompanying high-grade DCIS had a 2.5-fold higher probability of local or distant relapse than did those with IDC and low-grade DCIS (hazard ratio, 2.51; 95% confidence interval, 1.12-5.64).

CONCLUSIONS

The prognosis of patients with invasive breast cancer differed according to the grade of concomitant adjacent DCIS. Accordingly, the grade of adjacent DCIS should be considered as a prognostic factor in the clinical management of patients with breast cancer. However, in our study, the follow-up periods were short to confirm prognostic effect. Further studies are needed.

Invasive cancers are not necessarily from preformed in situ tumours - an alternative way of carcinogenesis from misplaced stem cells

Cancers are thought to be the result of accumulated gene mutations in cells. Carcinomas, which are cancers arising from epithelial tissues usually go through several stages of development: atypical hyperplasia, carcinoma in situ and then invasive carcinoma, which might further metastasize. However, we think that the present pathological data are enough to prove that there might be an alternative way of carcinogenesis. We propose that majority of invasive cancers arise in the connective tissue stroma de novo, from the misplaced epithelial stem cells which come to the wrong land of connective tissue stroma by accident. The in situ carcinomas, which are mostly curable, should not be considered genuine cancer, but rather as quasi-cancer. We design this new theory of carcinogenesis as the stem cell misplacement theory (SCMT). Our SCMT theory chains together other carcinogenesis theories such as the inflammation-cancer chain, the stem cell theory and the tissue organization field theory. However, we deny the pathway of somatic mutation theory as the major pathway of carcinogenesis.

Loss of HITS (FAM107B) expression in cancers of multiple organs: tissue microarray analysis

Family with sequence similarity 107 (FAM107) proteins consist of two subtypes, FAM107A and FAM107B in mammals, possessing a conserved N-terminal domain of unknown function. Recently we found that FAM107B, an 18 kDa nuclear protein, is expressed in a broad range of tissues and is downregulated in gastrointestinal cancer. Because FAM107B expression is amplified by heat-shock stimulation, we designated it heat shock-inducible tumor small protein (HITS). Although data related to FAM107A as a candidate tumor suppressor have been accumulated, little biological information is available for HITS. In the present study, we examined HITS expression using immunohistochemistry with tissue microarrays and performed detailed statistical analyses. By screening a high-density multiple organ tumor and normal tissue microarray, HITS expression was decreased in tumor tissues of the breast, thyroid, testis and uterine cervix as well as the stomach and colon. Further analysis of tissue microarrays of individual organs showed that loss of HITS expression in cancer tissues was statistically significant and commonly observed in distinct organs in a histological type-specific manner. The HITS expression intensity was inversely correlated with the primary tumor size in breast and thyroid cancers. In addition, effects of tetracycline-inducible HITS expression on tumor growth were investigated in vivo. Forced expression of HITS inhibited tumor xenograft proliferation, compared with the mock-treated tumor xenograft model. These results show that loss of HITS expression is a common phenomenon observed in cancers of distinct organs and involved in tumor development and proliferation.

Coexisting ductal carcinoma in situ independently predicts lower tumor aggressiveness in node-positive luminal breast cancer

Primary breast invasive ductal carcinoma coexisting with ductal carcinoma in situ (IDC-DCIS) is characterized by lower proliferation rate and metastatic propensity than size-matched pure IDC. IDC-DCIS is also more often ER-positive, PR-positive and/or HER2-positive. This analysis aims to clarify whether the presence of coexisting DCIS in IDC affects tumor aggressiveness in various biological subtypes of breast cancer, respectively. Tumor data obtained from 1,355 consecutive female patients undergoing upfront surgery for primary breast cancer were analyzed retrospectively; 196 patients with pure DCIS were excluded. Based on evidence that immunohistochemistry (IHC) provides a reasonable approximation of molecular phenotypes, the tumor samples were divided into 4 groups: (1) luminal A (ER and/or PR-positive, HER2-negative, Ki67 ≤ 12), (2) luminal B (ER and/or PR-positive, HER2-negative, Ki67 > 12), (3) HER2 (HER2-positive) and (4) basal-like (triple-negative) disease. Ki67 expression and nodal involvement of IDC with or without DCIS in these groups were compared. The number of patients with luminal A, luminal B, HER2 and basal-like breast cancer were 396, 265, 258 and 117, respectively. Ki-67 was lower in IDC-DCIS than in size-adjusted pure IDC of both luminal A and luminal B subtypes (P = 0.15 and <0.005, respectively). In HER2 or basal-like tumors, there were no significant difference between pure IDC and IDC-DCIS. The presence of coexisting DCIS in IDC predicts lower biological aggressiveness in luminal cancers but not in the conventionally more aggressive HER2-positive and triple-negative subtypes.

Recent advances and current controversies in the management of DCIS of the breast

Ductal carcinoma in situ (DCIS) is commonly diagnosed today, mainly due to widespread use of screening mammography. Despite a better understanding of its biological behavior, many issues regarding its optimal management remain controversial. The biological behavior of DCIS has been associated with distinct molecular and histological features (such as expression of COX2, Ki67, c-erbB2, p53 mutation, presence or absence of comedonecrosis, nuclear grade, hormone receptor status, etc.). Recent advances in the diagnosis of DCIS include using magnetic resonance imaging, and the use of stereotactic-guided directional vacuum-assisted biopsy (DVAB). Ductoscopy and ductal lavage have a limited role in the management of DCIS. Surgical treatment of DCIS includes simple local excision to various forms of wider excision (segmental resection or quadrantectomy), or even mastectomy (either simple or skin-sparing). Radiotherapy following breast-conserving surgery significantly reduces local recurrence rates. Axillary lymph node dissection is not required for the management of DCIS; however, during the last decade, sentinel lymph node biopsy is increasingly used to exclude the presence of axillary metastases (when invasive disease is present within the DCIS). This approach has many advantages (including the avoidance of a second surgery if invasive disease is diagnosed within the DCIS) and should be considered when there is an increased probability for the presence of invasive breast cancer within the DCIS. The role of other minimally invasive methods (such as the "therapeutic" application of the DVAB technique, radiofrequency ablation, laser therapy, cryotherapy and brachytherapy) in the management of small DCIS remains unproven. Tamoxifen should be considered in the management of selected patients with DCIS, such as patients with hormone receptor positive DCIS, young patients, and patients without risk factors for potential side effects. Additionally, and controversial, there is evidence that aromatase inhibitors may be better than tamoxifen in the management of DCIS.

Ductal carcinoma in situ: a review of recent advances

PURPOSE OF REVIEW

This review summarizes recent findings on ductal carcinoma in situ of the breast and their impact on prognosis and management of the disease.

RECENT FINDINGS

Great advances have been made in our understanding of ductal carcinoma in situ. Nuclear grading is probably the most important pathological factor that affects clinical outcome and correlates with distinct genetic pathways. Identifying key molecules in each pathway may provide better markers for prognostic, predictive and therapeutic purposes. Not all cases of ductal carcinoma in situ will progress to invasive ductal carcinoma, and identifying this subgroup of patients should lead to a reduction of overtreatment. Progenitor cell theory at the cellular level and sick lobe theory at the architectural level may help provide a better understanding of ductal carcinoma in situ from a different perspective and facilitate the development of individualized therapy. Prevention of local recurrence is the primary goal for treatment. Debate continues, however, on the use of radiotherapy, hormonal therapy, and sentinel lymph node biopsy. A panel of molecular markers may be needed for accurately predicting clinical outcome for the disease.

SUMMARY

Understanding the carcinogenesis of ductal carcinoma in situ at the molecular level may lead to an optimal individualized therapy with minimal over or undertreatment.