Microinvasive ductal carcinoma (T1mic) of the breast. The clinicopathological profile and immunohistochemical features of 28 cases

Clinicopathological characteristics and prognosis of microinvasive breast cancer: A population-based analysis

OBJECTIVES

Microinvasive breast cancer (MIBC) is a special type of breast cancer with a relatively low prevalence, of which the understanding remains controversial. In this article, we aimed to clarify the clinicopathological characteristics and prognosis of MIBC in the setting of different molecular subtypes and give feasible suggestions on clinical practice in MIBC.

METHODS

This study utilized the data from Surveillance, Epidemiology, and End Results (SEER) database. Patients were divided into subgroups based on the molecular subtypes, of which the clinicopathological characteristics were further undergone comparative analyses. Kaplan-Meier method and Cox proportional hazard regression analysis were employed to determine the prognosis of the subtypes, and to explore the prognostic factors. Patients were randomly assigned in a 7:3 ratio to the training and validation cohorts. The independent risk variables were then adopted to generate a nomogram to predict the 3- and 5-year survival probability.

RESULTS

A total of 4301 MIBC patients between 2010 and 2016 were obtained from the SEER database, which were subsequently separated into HR+/HER2- (n = 2598), HR+/HER2+ (n = 723), HR-/HER2+ (n = 633), and HR-/HER2- (n = 347) groups. The HR+/HER2+ group showed the best overall survival (OS) (81.28 months, 95% CI 80.45-82.11) compared with other groups (p = 0.0089). The application of radiotherapy in HR+/HER2- and HR+/HER2+ MIBC patients brought out additional survival benefit compared with those without radiotherapy (p < 0.0001 and p = 0.024, respectively). The prognosis among four subgroups with or without chemotherapy showed no statistical difference. Based on the curated nomogram, the high-score group exhibited a better OS compared with patients from the low-score group.

CONCLUSIONS

Profound heterogeneity was detected among different molecular subtypes in MIBC patients, of which HR+/HER2+ subtype presented the best prognosis. For HR-positive MIBC patients, increasing survival benefits could be retrieved from radiotherapy. Chemotherapy was not recommended for patients with MIBC. Individual-based protocols were introduced based on the nomogram which warranted further validation.

Clinical and imaging characteristics of breast ductal carcinoma in situ with microinvasion

Background

We analyzed the clinical and imaging characteristics of patients with breast ductal carcinoma in situ with microinvasion (DCISM) and breast ductal carcinoma in situ (DCIS).

Methods

We analyzed the records of 40 patients diagnosed with DCISM and 61 patients with DCIS who were hospitalized at Shengjing Hospital (Shenyang, China) from January 2009 to June 2016. The size, hardness, and degree of calcification of tumors were determined by mammography and ultrasonography.

Results

In all, 37 DCISM patients and 45 DCIS patients showed clinical palpable masses (92.5% vs 73.77%, P = 0.018). Mammography showed that the mean size of tumor was larger in DCISM patients than that of DCIS patients (3.13 ± 1.51 vs 2.68 ± 1.77, P = 0.030). Ultrasound examination revealed calcification shadows in the solid tumor mass in 17 DCISM cases and 11 DCIS patients (42.5 vs 18.03%, P = 0.007). Furthermore, estrogen receptor positivity and progesterone receptor positivity were more common in DCIS patients (32.5% vs 54.10%, P = 0.033; 22.5% vs 45.90%, P = 0.017), and the percentage of menopausal patients were higher in DCISM patients than that of DCIS patients (70.00% vs 47.54%, P = 0.026).

Conclusion

Clinically palpable and calcified tumor masses on sonography are more commonly encountered in DCISM lesions.

Breast ductal Carcinoma in situ associated with microinvasion induces immunological response and predicts ipsilateral invasive recurrence

Although microinvasion (Mi) is often thought to be an interim stage between ductal carcinoma in situ (DCIS) and established invasive ductal carcinoma, survival outcomes and biological behaviour of DCIS-Mi are still poorly understood. This study investigated the potential influence of Mi on disease-free survival (DFS) and assessed its correlations with clinicopathological parameters, prognosis, molecular, and immune markers. CD4, CD8, forkhead box P3 (FOXP3), CD68, CD163, programmed cell death protein 1 (PD-1), and its ligand (PD-L1) expression in pure DCIS and DCIS-Mi, from a cohort of 198 patients, were determined by immunohistochemistry. DFS, clinicopathological parameters, immune markers, and biomarker expression were correlated with presence of Mi. Twelve out of 198 DCIS cases were associated with Mi. DCIS-Mi was significantly linked with ipsilateral invasive recurrence (p = 0.032). Kaplan-Meier analysis revealed that DCIS-Mi had worse DFS for ipsilateral invasive recurrence (p = 0.011) and this was affirmed by multivariate Cox regression analysis (95% CI 1.181-9.010, HR = 3.262, p = 0.023). DCIS-Mi was associated with higher densities of immune infiltrates positive for CD4 (p = 0.037), FOXP3 (p = 0.037), CD163 (p = 0.01), and PD-L1 (p = 0.015). This study demonstrated that DCIS-Mi was correlated with high densities of immune infiltrates and predicted ipsilateral invasive recurrence.

Sentinel lymph node biopsy in microinvasive ductal carcinoma in situ

BACKGROUND

Microinvasive breast cancer is an uncommon pathological entity. Owing to the rarity of this condition, its surgical axillary management and overall prognosis remain controversial.

METHODS

A database was analysed to identify patients with microinvasive ductal carcinoma in situ (DCIS) who had surgery for invasive breast cancer at the European Institute of Oncology, Milan, between 1998 and 2010. Women who had undergone axillary staging by sentinel lymph node biopsy were included in the study.

RESULTS

Of 257 women with microinvasive breast cancer who underwent sentinel lymph node biopsy (SLNB), 226 (87·9 per cent) had negative sentinel lymph nodes (SLNs) and 31 had metastatic SLNs. Twelve patients had isolated tumour cells (ITCs), 14 had micrometastases and five had macrometastases in sentinel nodes. Axillary lymph node dissection was performed in 16 of the 31 patients with positive SLNs. After a median follow-up of 11 years, only one regional first event was observed in the 15 patients with positive SLNs who did not undergo axillary lymph node dissection. There were no regional first events in the 16 patients with positive SLNs who had axillary dissection.

CONCLUSION

Good disease-free and overall survival were found in women with positive SLNs and microinvasive DCIS. This study is in line with studies showing that SLNB in microinvasive DCIS may not be useful, and supports the evidence that less surgery can provide the same level of overall survival with better quality of life.

Stromal characteristics are adequate prognosticators for recurrence risk in ductal carcinoma in situ of the breast

BACKGROUND

Ductal carcinoma in situ (DCIS) of the breast constitutes a heterogeneous group of non-obligate precursors for invasive breast cancer. To date, adequate risk stratification is lacking, which is presumed to result in overtreatment. We previously identified myxoid stromal architecture as a potential prognosticator for loco-regional recurrence. In the present study, we investigated the prognostic potential of stromal characteristics.

METHODS

Hematoxylin and eosin stained slides from 211 DCIS patients were reviewed. The following histological features were dichotomously assessed: nuclear grade, DCIS architecture, presence of necrosis, intraductal calcifications, stromal inflammation and myxoid stromal architecture. Loco-regional recurrences constituted the primary endpoint.

RESULTS

Cox regression analysis showed that high nuclear grade, myxoid stromal architecture and moderate to extensive stromal inflammation were significantly associated with decreased recurrence-free survival, independent of radiotherapy. Based on these features, a combined risk score (CRS) was calculated, ranging from zero to three. A high CRS of three was associated with significantly shorter recurrence-free survival. Nineteen patients had a CRS of three, of which three relapsed (15.7%), whereas only one out of 113 patients with a CRS of zero relapsed (0.9%).

CONCLUSIONS

We were able to validate our previously reported findings regarding the prognostic potential of myxoid periductal stroma in an independent DCIS patient cohort. A CRS based on nuclear grade, myxoid stromal architecture and stromal inflammation might facilitate discrimination of low risk from high risk patients. Consequently, the CRS may tailor adjuvant therapy. Future research should investigate whether radiotherapy can be safely omitted in patients with a low CRS.

Analysis of tumour-infiltrating lymphocytes reveals two new biologically different subgroups of breast ductal carcinoma in situ

Background

Tumour-infiltrating lymphocytes (TILs) have been demonstrated to significantly influence prognosis and response to therapy of invasive breast cancer (IBC). Thus, it has been suggested that TIL density or/and immunophenotype could serve as biomarkers for selection of IBC patients for immunotherapy. However, much less is known about significance of TILs in breast ductal carcinoma in situ (DCIS).

Methods

We retrospectively investigated TIL density and immunophenotype in 96 pure DCIS and 35 microinvasive carcinomas (miCa). TIL density was assessed on H&E-stained breast biopsy sections as the percentage of tumour stromal area occupied by TILs, and classified into 4 grades: 0 (0%–9%), 1 (10–29%), 2 (30–49%) and 3 (50%–100%). TIL immunophenotype was assessed by immunohistochemistry for CD8, CD4, FoxP3, CD38 or CD20.

Results

Compared to pure DCIS, miCa contained significantly more cases with TIL density grade 3 (p = 0.028). Concordantly, CD8+, CD4+ and CD38+ cells were more numerous in miCa than in pure DCIS. In the pure DCIS subgroup with TIL density grades 2 and 3, all TIL subpopulations were more numerous than in the pure DCIS with TIL density grades 0 and 1, however the ratio between T-lymphocytes (CD8+ and CD4+) and B-lymphocytes (CD20+) was significantly lower (p = 0.029). On the other side, this ratio was significantly higher in miCa, in comparison with pure DCIS having TIL density grades 2 and 3 (p = 0.017). By cluster analysis of tumour cell pathobiological features we demonstrated similarity between miCa and the pure DCIS with TIL density grades 2 and 3. The only significant difference between those two categories was in the ratio of T- to B-TILs, higher in miCa.

Conclusion

Results indicate that TIL density level can distinguish 2 biologically different DCIS subgroups, one of which (DCIS with ≥30% TILs, the TIL-rich DCIS) is like miCa. Similarity of TIL-rich pure DCIS and miCa as well as the role of B-lymphocytes in DCIS invasiveness are worth further investigating with regards to the potential development of immunotherapy-based prevention of DCIS progression.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4013-6) contains supplementary material, which is available to authorized users.

Impact of microinvasion on breast cancer mortality in women with ductal carcinoma in situ

BACKGROUND

Ductal carcinoma in situ (DCIS) is a neoplastic proliferation of epithelial cells which is confined within the basement membrane of the mammary ductal-lobular system. It is of interest to determine to what extent the potential to metastasize increases for DCIS patients when the basement membrane is breached (i.e. microinvasion is present).

METHODS

We retrieved the records of 525,395 women who had either first primary DCIS or small (≤ 2.0 cm) node-negative invasive breast cancer in the Surveillance, Epidemiology and End Results (SEER) registries database (1990-2013). For each patient, we extracted information on year of diagnosis, age at diagnosis, tumour size, tumour grade, oestrogen receptor status, use of radiotherapy, type of surgery, cause of death and follow-up time. We classified patients into four groups, according to the size of the invasive component of the primary tumour. We estimated the actuarial rate of breast cancer-specific mortality at ten and 20 years for women in each size category.

RESULTS

We identified 161,394 women with pure DCIS, 13,489 women with microinvasive carcinoma (≤ 0.1 cm of invasion), 153,856 women with invasive cancer 0.2-1.0 cm in size and 196,656 women with invasive cancer 1.1-2.0 cm in size. The 20-year actuarial breast cancer-specific mortality rate was 3.8% for women with pure DCIS, was 6.9% for women with microinvasive carcinoma, was 6.8% for women with invasive cancer 0.2-1.0 cm in size and was 12.1% for women with invasive cancer 1.1-2.0 cm in size. The adjusted hazard ratio for death associated with microinvasive carcinoma (vs. pure DCIS) was 2.00 (95% CI 1.76-2.26; p < 0.0001).

CONCLUSIONS

In terms of prognosis, microinvasive cancer more closely resembles small invasive cancer 0.2-1.0 cm) than pure DCIS. For invasive cancers under 1.0 cm, size has little impact on mortality.

The Demographic Features, Clinicopathological Characteristics and Cancer-specific Outcomes for Patients with Microinvasive Breast Cancer: A SEER Database Analysis

To investigate the clinicopathological characteristics and survival outcomes of microinvasive breast cancer, we conducted an observational study of female diagnosed with DCIS or DCIS with microinvasion (DCISM) from 1990 to 2012 using the Surveillance, Epidemiology, and End Results (SEER) database. There were 87695 DCIS and 8863 DCISM identified. In DCISM group, patients appeared to be younger and more black patients were identified in comparison with DCIS group. Furthermore, DCISM was associated with more aggressive tumor characteristics like higher rates of oestrogen receptor (ER) and progesterone receptor (PR) negativity, HER2 positivity, and lymph node metastasis. With a median follow-up of 91 months, patients with DCISM had worse cancer-specific survival (CSS) (hazard ratio [HR], 2.475; P < 0.001) and overall survival (OS) (HR, 1.263; P < 0.001). In the multivariable analysis, microinvasion was an independent prognostic factor for worse CSS (HR, 1.919; P < 0.001) and OS (HR, 1.184; P < 0.001). The 10-year cancer-specific mortality rate was 1.49% in DCIS and 4.08% in DCISM (HR, 2.771; P < 0.001). The 20-year cancer-specific mortality rate was 4.00% in DCIS and 9.65% in DCISM (HR, 2.482; P < 0.001). Deepening understanding of the nature of microinvasive breast cancer will be valuable for clinical treatment recommendations.

Is adjuvant chemotherapy necessary for patients with microinvasive breast cancer after surgery?

Objective: Survival and treatment of patients with microinvasive breast cancer (MIBC) remain controversial. In this paper, we evaluated whether adjuvant chemotherapy is necessary for patients with MIBC to identify risk factors influencing its prognosis and decide the indication for adjuvant chemotherapy. Methods: In this retrospective study, 108 patients with MIBC were recruited according to seventh edition of the staging manual of the American Joint Committee on Cancer (AJCC). The subjects were divided into chemotherapy and non-chemotherapy groups. We compared the 5-year disease-free survival (DFS) and overall survival (OS) rates between groups. Furthermore, we analyzed the factors related to prognosis for patients with MIBC using univariate and multivariate analyses. We also evaluated the impact of adjuvant chemotherapy on the prognostic factors by subgroup analysis after median follow-up time of 33 months (13-104 months). Results: The 5-year DFS and OS rates for the chemotherapy group were 93.7% and 97.5%, whereas those for the non-chemotherapy group were 89.7% and 100%. Results indicate that 5-year DFS was superior, but OS was inferior, in the former group compared with the latter group. However, no statistical significance was observed in the 5-year DFS (P=0.223) or OS (P=0.530) rate of the two groups. Most relevant poor-prognostic factors were Ki-67 overexpression and negative hormonal receptors. Cumulative survival was 98.2% vs. 86.5% between low Ki-67 (≤20%) and high Ki-67 (>20%). The hazard ratio of patients with high Ki-67 was 16.585 [95% confidence interval (CI), 1.969-139.724; P=0.010]. Meanwhile, ER(-)/PR(-) patients with MIBC had cumulative survival of 79.3% compared with 97.5% for ER(+) or PR(+) patients with MIBC. The hazard ratio for ER(-)/PR(-) patients with MIBC was 19.149 (95% CI, 3.702-99.057; P<0.001). Subgroup analysis showed that chemotherapy could improve the outcomes of ER(-)/PR(-) patients (P=0.014), but not those who overexpress Ki-67 (P=0.105). Conclusions: Patients with MIBC who overexpress Ki-67 and with negative hormonal receptors have relatively substantial risk of relapse within the first five years after surgery. However, adjuvant chemotherapy can only improve the outcomes of ER(-)/PR(-) patients, but not those who overexpress Ki-67. Further studies with prolonged follow-up of large cohorts are recommended to assess the prognostic significance and treatment of this lesion.

Re-evaluating the role of sentinel lymph node biopsy in microinvasive breast carcinoma

The role of sentinel lymph node biopsy in microinvasive breast carcinoma is unclear. We examined the incidence of lymph node metastasis in patients with microinvasive carcinoma who underwent surgery at our institution. Retrospective review of our pathology database was performed (1994-2012). Of 7000 patients surgically treated for invasive breast carcinoma, 99 (1%) were classified as microinvasive carcinoma. Axillary staging was performed in 81 patients (64, sentinel lymph node biopsy; 17, axillary lymph node excision). Seven cases (9%) showed isolated tumor/epithelial cells in sentinel nodes. Three of these seven cases showed reactive changes in lymph nodes, papillary lesions in the breast with or without displaced epithelial cells within biopsy site tract, or immunohistochemical (estrogen receptor, progesterone receptor, and HER2) discordance between the primary tumor in the breast and epithelial cells in the lymph node, consistent with iatrogenically transported epithelial cells rather than true metastasis. The remaining four cases included two cases, each with a single cytokeratin-positive cell in the subcapsular sinus detected by immunohistochemistry only, and two cases with isolated tumor cells singly and in small clusters (<20 cells per cross-section) by hematoxylin and eosin and immunohistochemistry. The exact nature of cytokeratin-positive cells in the former two cases could not be determined and might still have represented iatrogenically displaced cells. In the final analysis, only two cases (3%) had isolated tumor cells. Three of these four cases had additional axillary lymph nodes excised, which were all negative for tumor cells. At a median follow-up of 37 months (range 6-199 months), none of these patients had axillary recurrences. Our results show very low incidence of sentinel lymph node involvement (3%), only as isolated tumor cells, in microinvasive carcinoma patients. None of our cases showed micrometastases or macrometastasis. We recommend reassessment of the routine practice of sentinel lymph node biopsy in patients with microinvasive carcinoma.

Histopathological characterization of ductal carcinoma in situ (DCIS) of the breast according to HER2 amplification status and molecular subtype

This study aimed to characterize ductal carcinoma in situ (DCIS) according to human epidermal growth factor receptor 2 (HER2) amplification status and molecular subtype. In addition, we performed a detailed HER2 and CEP17 copy number analysis and we assessed the impact of recent changes in the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines on HER2 immunohistochemical (IHC) scores in DCIS. Nuclear grade, extensive comedonecrosis, stromal architecture, stromal inflammation, and progesterone receptor (PR) expression were significantly associated with HER2 amplification status. In multivariate analysis, stromal inflammation and extensive comedonecrosis were the only two features that remained significantly related to HER2 amplification status. The recent changes in ASCO/CAP guidelines resulted in significant upgrading of HER2 IHC score. Remarkably, about one in five non-amplified DCIS presented a 3+ IHC score, regardless of the scoring method. The biological significance of this phenomenon is presently unknown. After categorization according to molecular subtype, luminal A DCIS mainly presented histopathological features associated with good prognosis, whereas luminal B/HER2+ and HER2+ categories displayed a more aggressive phenotype. Overall, our results demonstrate that HER2-amplified DCIS constitute a clearly distinct subgroup which is characterized by histopathological features associated with poor prognosis. Further studies are required to elucidate the biological significance of a 3+ IHC score in non-amplified DCIS, as well as its mechanism.

Underestimation of invasive lesions in patients with ductal carcinoma in situ of the breast diagnosed by ultrasound-guided biopsy: a comparison between patients with and without HER2/neu overexpression

PURPOSE

To determine the rate of underestimation of ductal carcinoma in situ (DCIS) diagnosed at imaging-guided biopsy and to analyze its association with HER2/neu oncogene, an important biomarker in assessing the tumour aggressiveness and guiding hormone therapy for breast cancer.

METHODS

We retrospectively reviewed 162 patients with DCIS diagnosed by imaging-guided core needle biopsy between January 2008 and March 2013. All of these patients received surgical excision, and in 25, the diagnosis was upgraded to invasive breast cancer. In this study, we examined the ultrasound, mammographic features and histopathological results for each patient, and compared these parameters between those with and without HER2/neu overexpression.

RESULTS

Of the 162 DCIS lesions, 110 (67.9%) overexpressed HER2/neu. Nineteen patients with HER2/neu overexpressing DCIS (n=19/110, 17.3%) were upgraded after surgery to a diagnosis of invasive breast cancer. In this group, the upgrade rate was highest in patients with a dilated mammary duct pattern (42.1%, n=8/19, p=0.02) and the presence of abnormal axillary nodes (40.0%, n=12/30, p<0.01) at ultrasound and was significantly associated with comedo tumour type on pathology.

CONCLUSIONS

Biopsy may underestimate the invasive component in DCIS patients. Sonographic findings of dilated mammary ducts and presence of abnormal axillary lymph nodes may help predicting the invasive components and possibly driving more targeted biopsy procedures.

Extensive pure ductal carcinoma in situ of the breast: identification of predictors of associated infiltrating carcinoma and lymph node metastasis before immediate reconstructive surgery

AIM

To identify predictors for infiltrating carcinoma and lymph node involvement, before immediate breast reconstructive surgery, in patients with an initial diagnosis of extensive pure ductal carcinoma in situ of the breast (DCIS).

PATIENTS AND METHODS

Between January 2000 and December 2009, 241 patients with pure extensive DCIS in preoperative biopsy had underwent mastectomy. Axillary staging (sentinel node and/or axillary dissection) was performed in 92% (n = 221) of patients. Patients with micro-invasive lesions at initial diagnosis, recurrence or contralateral breast cancer were excluded.

RESULTS

Respectively 14% and 21% of patients had a final diagnosis of micro-invasive carcinoma (MIC) and invasive ductal carcinoma (IDC). Univariate analysis showed that the following variables at diagnosis were significantly correlated with the presence of either MIC or IDC in the mastectomy specimen: palpable tumor (p = 0.002), high grade DCIS (p = 0.002) and detection of an opacity by mammography (p = 0.019). Axillary lymph node (ALN) involvement was reported in 9% of patients. Univariate analysis suggested that a body mass index higher than 25 (p = 0.007), a palpable tumor (p = 0.012) and the detection of an opacity by mammography (p = 0.044) were associated with an increased rate of ALN involvement.

CONCLUSION

Skin-sparing mastectomy and immediate breast reconstruction (IBRS) has become increasingly popular, especially for patients with extended DCIS of the breast. This study confirmed that extended DCIS is associated with a substantial risk of finding MIC or IDC on the surgical specimen but also ALN involvement. Adjuvant systemic treatment and/or radiotherapy could be indicated for some of these patients after the surgery. Patients should be informed of the rate of 1) complications associated to IBRS that will potentially delay the introduction of systemic or local therapy 2) complications associated to radiotherapy after IBRS.

MR features to suggest microinvasive ductal carcinoma of the breast: can it be differentiated from pure DCIS?

BACKGROUND

Morphologic and kinetic characteristics of breast lesions are regarded as a major criterion for their differential diagnosis in dynamic magnetic resonance imaging (MRI). However, there have not been well-reported MRI findings of microinvasive ductal carcinoma.

PURPOSE

To evaluate MRI characteristics of microinvasive ductal carcinoma of the breast and to compare MRI findings in patients with microinvasive ductal carcinoma and pure ductal carcinoma in situ (DCIS).

MATERIAL AND METHODS

Eighty-one patients with pathologically confirmed microinvasive ductal carcinomas (n = 37) or pure DCIS (n = 44) were included in this study. The MRI findings were analyzed without knowledge of the pathologic and conventional imaging findings. For all the lesions detected on MRI, morphologic and kinetic analyses were performed according to the Breast Imaging Reporting and Data System. For the non-mass lesions, the presence of clustered ring enhancement was also analyzed. Statistical analyses were performed using Student's t test, χ(2) test, and Fisher's exact test.

RESULTS

In total 35 cases of microinvasive ductal carcinoma and 39 cases of DCIS were detected on MRI. The most common and dominant MRI findings of microinvasive ductal carcinoma and DCIS were non-mass lesions with heterogeneous enhancement. However, the spiculated margin of the mass-type lesion (P = 0.022), the segmental distribution (P = 0.023), and clustered ring enhancement (P = 0.006) of the non-mass-type lesion, and the enhancement kinetics showing strong initial enhancement (P = 0.004) with subsequent wash-out (P = 0.001) were significantly more frequent in microinvasive ductal carcinoma than in DCIS.

CONCLUSION

Non-mass lesions with segmental distribution, heterogeneous enhancement, and strong initial enhancement with a wash-out curve were the dominant MRI findings of microinvasive ductal carcinoma. Compared with DCIS, microinvasive ductal carcinoma showed more suspicious imaging characteristics. For the non-mass lesions, clustered ring enhancement was also a characteristic finding of microinvasion on MRI.

Ocimum gratissimum retards breast cancer growth and progression and is a natural inhibitor of matrix metalloproteases

Ocimum genus (a.k.a holy basil or tulsi) is a dietary herb used for its multiple beneficial pharmacologic properties including anti-cancer activity. Here we show that crude extract of Ocimum gratissimum (OG) and its hydrophobic and hydrophilic fractions (HB and HL) differentially inhibit breast cancer cell chemotaxis and chemoinvasion in vitro and retard tumor growth and temporal progression of MCF10ADCIS.com xenografts, a model of human breast comedo-ductal carcinoma in situ (comedo-DCIS). OG-induced inhibition of tumor growth was associated with decreases in basement membrane disintegration, angiogenesis and MMP-2 and MMP-9 activities as confirmed by in situ gelatin zymography and cleavage of galectin-3. There was also decrease in MMP-2 and MMP-9 activities in the conditioned media of OG-treated MCF10AT1 and MCF10AT1-EIII8 premalignant human breast cancer cells as compared with control. The MMP-2 and MMP-9 inhibitory activities of OG were verified in vitro using gelatin, a synthetic fluorogenic peptide and recombinant galectin-3 as MMP substrates. Mice fed on OG-supplemented drinking water showed no adverse effects compared with control. These data suggest that OG is non-toxic and that the anti-cancer therapeutic activity of OG may in part be contributed by its MMP inhibitory activity.

Proposal for Creating a Guideline for Cancer Registration of Microinvasive Tumors of the Breast and Ovary (II)

BACKGROUND

Cancer registration in Korea has a longer than 30-years of history, during which time cancer registration has improved and become well-organized. Cancer registries are fundamental for cancer control and multi-center collaborative research. However, there have been discrepancies in assigning behavior codes. Thus, we intend to propose appropriate behavior codes for the International Classification of Disease Oncology, 3rd edition (ICD-O-3) for microinvasive tumors of the ovary and breast not only to improve the quality of the cancer registry but also to prevent conflicts.

METHODS

As in series I, two pathology study groups and the Cancer Registration Committee of the Korean Society of Pathologists (KSP) participated. To prepare a questionnaire on provisional behavior code, the relevant subjects were discussed in the workshop, and consensus was obtained by convergence of opinion from members of KSP.

RESULTS

Microinvasive tumor of the breast should be designated as a microinvasive carcinoma which was proposed as malignant tumor (/3). Serous borderline tumor with microinvasion of the ovary was proposed as borderline tumor (/1), and mucinous borderline tumor with microinvasion of the ovary as either borderline (/1) or carcinoma (/3) according to the tumor cell nature.

CONCLUSIONS

Some issues should be elucidated with the accumulation of more experience and knowledge. Here, however, we present our second proposal.

Significance of HER2 protein examination in ductal carcinoma in situ

BACKGROUND

HER2 expression is routinely checked in ductal carcinoma in situ, as in invasive ductal carcinoma. However, the effect of HER2 status in ductal carcinoma in situ on the development of malignancy and the significance of overexpression of HER2 are still not clear.

MATERIALS AND METHODS

We experienced 103 cases that were diagnosed as pure ductal carcinoma in situ from operative specimens in the 2-y period from 2006 to 2007. We examined their HER2 status and other markers. We added 38 cases of ductal carcinoma in situ with small invasive disease 5mm or less in diameter as subjects. We also examined how accurately HER2 status in biopsy specimens predicted the existence of an invasive component.

RESULTS

In pure ductal carcinoma in situ, tumors that were comedo type, high grade, or ER negative showed a high frequency of HER2 overexpression. In cases with small invasion, HER2 expression was higher than that in pure ductal carcinoma in situ. Among cases that were diagnosed as ductal carcinoma in situ by biopsy, 28% had invasive disease in operative specimens. In tumors that were palpable, large, or expressed HER2 3+ in biopsy samples, invasive disease was frequently observed in operative specimens.

CONCLUSIONS

Overexpression of HER2 in ductal carcinoma in situ might not always be necessary for progression to invasive ductal carcinoma. To clarify the significance of HER2 examination in DCIS, further investigations of the potential for invasive ductal carcinoma and the prognosis are still needed.

Microinvasive ductal carcinoma in situ: clinical presentation, imaging features, pathologic findings, and outcome

OBJECTIVE

The purpose of our study was to describe the clinical features, imaging characteristics, pathologic findings and outcome of microinvasive ductal carcinoma in situ (DCISM).

MATERIALS AND METHODS

The records of 21 women diagnosed with microinvasive ductal carcinoma in situ (DCISM) from November 1993 to September 2006 were retrospectively reviewed. The clinical presentation, imaging and histopathologic features, and clinical follow-up were reviewed.

RESULTS

The 21 lesions all occurred in women with a mean age of 56 years (range, 27-79 years). Clinical findings were present in ten (48%): 10 with palpable masses, four with associated nipple discharge. Mean lesion size was 21mm (range, 9-65mm). The lesion size in 62% was 15mm or smaller. Mammographic findings were calcifications only in nine (43%) and an associated or other finding in nine (43%) [mass (n=7), asymmetry (n=1), architectural distortion (n=1)]. Three lesions were mammographically occult. Sonographic findings available in 11 lesions showed a solid hypoechoic mass in 10 cases (eight irregular in shape, one round, one oval). One lesion was not seen on sonography. On histopathologic examination, all lesions were diagnosed as DCISM, with a focus of invasive carcinoma less than or equal to 1mm in diameter within an area of DCIS. Sixteen (76%) lesions were high nuclear grade, four (19%) were intermediate and one was low grade (5%). Sixteen (76%) had the presence of necrosis. Positivity for ER and PR was noted in 75% and 38%. Nodal metastasis was present in one case with axillary lymph node dissection. Mean follow-up time for 16 women was 36 months without evidence of local or systemic recurrence. One patient developed a second primary in the contralateral breast 3 years later.

CONCLUSION

The clinical presentation and radiologic appearance of a mass are commonly encountered in DCISM lesions (48% and 57%, respectively), irrespective of lesion size, mimicking findings seen in invasive carcinoma. Despite its potential for nodal metastasis (5% in our series), mean follow-up at 36 months was good with no evidence of local or systemic recurrence at follow-up. Knowledge of these clinical and imaging findings in DCISM lesions may alert the clinician to the possibility of microinvasion and guide appropriate management.

Comedo-ductal carcinoma in situ: A paradoxical role for programmed cell death

Comedo-DCIS is a histologic subtype of preinvasive breast neoplasia that is characterized by prominent apoptotic cell death and has greater malignant potential than other DCIS subtypes. We investigated the mechanisms of apoptosis in comedo-DCIS and its role in conversion of comedo-DCIS to invasive cancer. Clinical comedo-DCIS excisions and the MCF10DCIS.com human breast cancer model which produces lesions resembling comedo-DCIS were analyzed. Apoptotic luminal and myoepithelial cells were identified by TUNEL and reactivity to cleaved PARP antibody and cell death assessed by Western blotting, Mitocapture and immunohistochemical assays. MCF10DCIS.com cells undergo spontaneous apoptosis in vitro, both in monolayers and multicellular spheroids; it is associated with increased mitochondrial membrane permeability, increase in Bax/Bcl-2 ratio and occurs via caspase-9-dependent p53-independent pathway. This suggests that apoptosis is stromal-independent and that the cells are programmed to undergo apoptosis. Immunostaining with cleaved PARP antibody showed that myoepithelial apoptosis occurs before lesions progress to comedo-DCIS in both clinical comedo-DCIS and in vivo MCF10DCIS.com lesions. Intense staining for MMP-2, MMP-3, MMP-9 and MMP-11 was observed in the stroma and epithelia of solid DCIS lesions prior to conversion to comedo-DCIS in clinical and MCF10DCIS.com lesions. Gelatin zymography showed higher MMP-2 levels in lysates and conditioned media of MCF10DCIS. com cells undergoing apoptosis. These data suggest that signals arising from the outside (microenvironmental) and inside (internal genetic alterations) of the duct act in concert to trigger apoptosis of myoepithelial and luminal epithelial cells. Our findings implicate spontaneous apoptosis in both the etiology and progression of comedo-DCIS. It is possible that spontaneous apoptosis facilitates elimination of cells thus permitting expansion and malignant transformation of cancer cells that are resistant to spontaneous apoptosis.

Microinvasive breast cancer and the role of sentinel node biopsy: an institutional experience and review of the literature

Ductal carcinoma in situ with microinvasion (DCISM) is a distinct clinicopathologic entity. Its true metastatic potential has been unclear, due in part to historical differences in the definition of microinvasion. The role of routine axillary staging for DCISM is controversial, given the reportedly low incidence of axillary metastases. We describe our institutional experience with DCISM, and define the role of axillary staging. A retrospective analysis was made of patients with DCISM. Forty-four patients underwent axillary staging (24 axillary lymph node dissection [ALND], 22 sentinel node biopsy [SNB]). Macrometastatic disease was present in three patients (7%), and two patients had isolated tumor cells (itc) in the sentinel node. Patients with axillary metastases tended to be younger. Comedonecrosis, nuclear grade, multifocal microinvasion or presentation as a clinical mass was not associated with a higher rate of axillary metastases. In this series, 7% of patients had macrometastatic disease, and two patients (5%) had itc only. Axillary staging is indicated, and SNB is appropriate for the identification of axillary metastatic disease.

Focal degeneration of aged or injured myoepithelial cells and the resultant auto-immunoreactions are trigger factors for breast tumor invasion

The development of breast cancer is believed to be a multi-step process, sequentially progressing from normal to hyperplastic, to in situ, and to invasive stages. The progression from the in situ to invasive stage is believed to be triggered primarily, if not solely, by the overproduction of proteolytic enzymes by cancer cells, which cause degradation of the basement membrane. This theory is consistent with data derived from studies with cell cultures or animal models, while results from recent worldwide clinical trials with a variety of proteolytic enzyme inhibitors have been very disappointing, casting doubt on the validity of the enzyme theory. Based on our recent studies, we propose that breast tumor invasion is triggered by the following mechanisms and events: (1) the predisposition of genetic abnormalities in ME cell replenishment-related genes or other insults results in elevated focal degeneration of ME cells in some individuals; (2) the degradation products of ME cells or diffusible molecules of epithelial cells attract infiltration of immunoreactive cells (IRC) into the affected sites; (3) the direct physical contact between IRC and degenerated ME cells results in the discharge of digestive enzymes from IRC, causing focal disruptions in the ME cell layer; (4) focal disruptions in a given ME cell layer result in a localized loss of tumor suppressors and paracrine inhibitory function, a focal increase of permeability for oxygen, nutrients, and growth factors, and a localized increase of leukocyte infiltration, which facilitate the monoclonal proliferation of tumor progenitors, forming a biologically more aggressive cell cluster overlying the disrupted ME cell layer; (5) the direct physical contact between the newly formed cell cluster and stromal cells stimulates the production of tenascin and other invasion-associated molecules that facilitate tissue remodeling, angiogenesis, and epithelial-mesenchymal transition, providing a favorable micro-environment for proliferation and invasion. Our hypothesis differs from the enzyme theory in the stage of tumor invasion, the cellular origin of invasive lesions, the significance of IRC and stromal cells, and the potential approaches for treatment and prevention. If confirmed, our hypothesis could facilitate the early detection of specific individuals at increased risk to develop invasive breast cancer. More importantly, our hypothesis may facilitate development of novel approaches, including stimulating ME cell growth, neutralizing ME cell degradation products, manipulating the types and extent of IRC infiltration, and controlling the extent of stromal reactions, to combat tumor invasion.

Reliability of prognostic factors in breast carcinoma determined by core needle biopsy

OBJECTIVE

The aim of this study was to evaluate the reliability of information obtained by core needle biopsy (CNB).

METHODS

We studied 111 women (112 lesions) with breast cancer who underwent CNB and subsequent surgical excision. Six factors (histological type, nuclear grade, histological grade, estrogen receptor (ER) status, progesterone receptor (PR) status, and human epidermal growth factor receptor-2 (HER2) status) were evaluated in a blinded fashion at CNB and at surgical excision.

RESULTS

The histological type at CNB correlated exactly with that of the excisional specimen in 83% (87/105) of the cases. Of the 45 in situ lesions at CNB, 16 (36%) were found to have invasive carcinoma at surgical excision. The difference between the specimens from CNB and those from surgery in terms of the absolute concordance rate and kappa statistic value were 61% with a fair kappa value (0.26) in the nuclear grade, 75% with a moderate kappa value (0.55) in the histological grade, 95% with an almost perfect kappa value (0.84) in ER, 88% with a substantial kappa value (0.70) in PR and 88% with a substantial kappa value (0.65) in HER2. Regarding the evaluation of nuclear and histological grades, a trend toward greater accuracy was observed when thicker specimens were used.

CONCLUSIONS

CNB provided reliable information on the histological type of invasive carcinoma. It also evaluated ER, PR and HER2 (only in cases where the score was 3+) accurately in spite of the limited quantity of the specimen obtained with the thin (16-gauge) needle.

Sentinel lymph node metastasis from mammary ductal carcinoma in situ with microinvasion

Axillary lymph node dissection (ALND) in patients with ductal carcinoma in situ with microinvasion (DCISM) of the breast was controversial, because of the relevant morbidity incurred by the procedure and the low incidence of axillary involvement. The introduction of the sentinel lymph node (SLN) biopsy as a minimally invasive procedure for axillary staging has prompted new interest in this issue. However, as DCISM is a rare type of cancer, data on the incidence of SLN metastasis are scarce. The aim of the present paper was therefore to assess the prevalence of SLN metastasis in a multi-institutional series of DCISM patients, in order to ascertain whether SLN biopsy might be justified as a standard procedure in the presence of microinvasive cancer. Between 1999 and 2004, 43 patients with a diagnosis of DCISM underwent SLN biopsy. Microinvasion was defined as one or more foci of invasion beyond the basal membrane, none exceeding 1mm. SLNs were examined following haematoxylin-eosin and immunohistochemical staining. SLN metastases were found in four out of 43 cases (9.3%). In one patient, SLN contained only micrometastasis. All four patients with positive SLN underwent complete ALND and in all these cases further metastatic axillary nodes were found. In conclusion, given the relevant incidence of nodal metastases and the low morbidity of the procedure, we believe that SLN biopsy should be considered in all patients with a diagnosis of DCISM. In cases of SLN involvement, even if micrometastatic, our policy is to perform a complete ALND.

Ductal carcinoma in situ with microinvasion: Clinicopathologic study and biopathologic profile

Data regarding the biologic behavior and surgical management, in particular the axillary lymph node excision, of ductal carcinoma in situ with microinvasion (DCIS-MI) are controversial. Therefore, we decided to study the histopathologic characteristics, the biopathologic profile, as well as the follow-up of a group of patients with DCIS-MI. Thirty-one cases of DCIS-MI, 21 of whom were treated with axillary lymph node dissection, were studied. All cases were classified according to the Van Nuys classification, and the extension of DCIS was quantified. The biopathologic profile (ER, PR, MIB 1, p53, c-erbB-2) as well as the follow-up was also investigated. The results did not reveal any statistically significant differences between the two groups, and there was no statistically significant relationship between the extension of DCIS and the number of microinvasion (MI) foci or maximum MI diameter, or between Van Nuys classification of DCIS and again the number of MI foci or maximum MI diameter. DCIS-MI seems associated with good prognosis. None of the patients had relapses or metastases. Our data seem to suggest that the natural history of DCIS-MI resembles DCIS, and we, therefore, suggest that all the surgically removed area should be examined histologically to avoid missing foci of infiltrating breast cancer larger than 1mm.

Ductal Carcinoma in situ and related lesions of the breast: recent advances in pathology practice

The incidence of ductal carcinoma in situ (DCIS) of the breast has increased significantly in Japanese women. It comprises 14.1% (172/1216) of all primary breast cancers at our institute, and nowadays this histological type is familiar to the surgeons and pathologists of any institute. Several subclassifications have been published recently. Most based on nuclear atypia and the presence of comedonecrosis, and sometimes on the structures of the involved glands. These classifications are correlated with the biological behavior, tumor extent and the risk for local recurrences. The diagnostic accuracy of minimally invasive procedures (aspiration biopsy cytology/core needle biopsy) may differ between subclasses. Atypical ductal hyperplasia (ADH) and microinvasive ductal carcinomas are lesions which resemble but deviate from the DCIS spectrum. The incidence of ADH seems to be lower than in Western countries. Patients with ADH may have a risk for subsequent breast cancer, because ADH is frequently associated with contralateral breast carcinomas. Microinvasion should be treated with caution, but we could not find any metastatic foci in microinvasive ductal carcinomas (T1mic). Tentatively, ADH may be treated similarly to non-comedo (low-grade) DCIS cases, according to our limited clinical experience.