Barbara Del Curto

Adjuvant letrozole versus tamoxifen according to centrally-assessed ERBB2 status for postmenopausal women with endocrine-responsive early breast cancer: supplementary results from the BIG 1-98 randomised trial

BACKGROUND The Breast International Group (BIG) 1-98 trial (a randomised double-blind phase III trial) has shown that letrozole significantly improves disease-free survival (DFS) compared with tamoxifen in postmenopausal women with endocrine-responsive early breast cancer. Our aim was to establish whether the benefit of letrozole versus tamoxifen differs according to the ERBB2 status of tumours. METHODS The BIG 1-98 trial consists of four treatment groups that compare 5 years of monotherapy with letrozole or tamoxifen, and sequential administration of one drug for 2 years followed by the other drug for 3 years. Our study includes data from the 4922 patients randomly assigned to the two monotherapy treatment groups (letrozole or tamoxifen for 5 years; 51 months median follow-up [range <1 to 90 months]). A central assessment of oestrogen receptor (ER), progesterone receptor (PgR) and ERBB2 status using paraffin-embedded primary tumour material was possible for 3650 (74%) patients. ER, PgR, and ERBB2 expression were measured by immunohistochemistry (IHC) and ERBB2-positivity was confirmed by fluorescence in-situ hybridisation (FISH). Positive staining in at least 1% of cells was considered to show presence of ER or PgR expression. Tumours were deemed ERBB2-positive if amplified by FISH, or, for the few tumours with unassessable or unavailable FISH results, if they were IHC 3+. Hazard ratios (HR) estimated by Cox modelling were used to compare letrozole with tamoxifen for DFS, which was the primary endpoint, and to assess treatment-by-covariate interactions. The BIG 1-98 trial is registered on the clinical trials site of the US National Cancer Institute website http://www.clinicaltrials.gov/ct/show/NCT00004205. FINDINGS By central assessment 7% (257 of 3650) of tumours were classified as ERBB2-positive. In 3533 patients with tumours confirmed to express ER, DFS was poorer in patients with ERBB2-positive tumours (n=239) than in those with ERBB2-negative tumours (n=3294; HR 2.09 [95% CI 1.59-2.76]; p<0.0001). There was no statistical evidence of heterogeneity in the treatment effect according to ERBB2 status of the tumour (p=0.60 for interaction), thus, letrozole improves DFS compared with tamoxifen regardless of ERBB2 status. The observed HRs were 0.62 (95% CI 0.37-1.03) for ERBB2-positive tumours and 0.72 (0.59-0.87) for ERBB2-negative tumours. INTERPRETATION A benefit of letrozole over tamoxifen was noted, irrespective of ERBB2 status of the tumour, and, therefore, ERBB2 status does not seem to be a selection criterion for treatment with letrozole versus tamoxifen in postmenopausal women with endocrine-responsive early breast cancer.

BCL2, BCL6, MYC, MALT 1, and BCL10 rearrangements in nodal diffuse large B-cell lymphomas: a multicenter evaluation of a new set of fluorescent in situ hybridization probes and correlation with clinical outcome ☆

Diffuse large B-cell lymphoma is the most common type of non-Hodgkin lymphoma. Although it is a curable disease, fewer than half of patients are cured with conventional chemotherapy. The highly variable outcome reflects a heterogeneous group of tumors, with different genetic abnormalities and responses to therapy. We analyzed 74 cases of diffuse large B-cell lymphoma using interphase fluorescent in situ hybridization with commercially available probes for split-signal targeting BCL-2, BCL-6, MYC, BCL-10, and MALT-1. Gene rearrangements were identified in 48 (65%) of 74 cases. BCL-6 was the most rearranged gene (45%), followed by BCL-2 (21%), BCL-10 (18%), and MYC (16%). No MALT-1 rearrangements were found. When diffuse large B-cell lymphoma cases were subdivided into germinal-center B-cell-like and activated B-cell-like groups, an inverse pattern of BCL-2 and BCL-6 rearrangements was observed. Of interest, the presence of chromosome rearrangements was associated with a worse prognosis. The pattern of cytogenetic abnormalities highlighted the fact not only that diffuse large B-cell lymphoma is a heterogeneous entity but also that even individual cases may contain subclones bearing different chromosomal rearrangements. The relevance and the clinical implication of minor clones showing gene rearrangements are poorly understood; however, this first observation suggests that different rearrangements may be involved in the progression of the disease. The fluorescent in situ hybridization analysis with the panel used in this study is useful to detect the heterogeneity of diffuse large B-cell lymphomas and identify alterations with prognostic implications.

The transactivating isoforms of p63 are overexpressed in high-grade follicular lymphomas independent of the occurrence of p63 gene amplification

p63 is a p53‐related gene mapping to 3q28 that codes for multiple mRNA transcripts with (TA‐p63) or without (ΔN‐p63) transactivating effects on genes that promote cell differentiation and apoptosis. We analysed p63 alterations by immunohistochemistry, quantitative real‐time RT‐PCR and FISH in a series of 45 follicular lymphomas (FL). None of the tumours showed immunoreactivity for the p40 antibody, which recognizes only the truncated isoforms of p63, or ΔN‐p63 mRNA expression. Immunoreactivity for the 4A4 antibody, which recognizes both the transactivating and the truncated p63 isoforms, was found in 5 ± 5.5%, 6.85 ± 4.88% and 33.2 ± 22.31% of grade I, II and III FL cells, respectively (p < 0.0001). Quantitative RT‐PCR analysis showed that all cases but one had TA‐p63 mRNA levels higher than non‐neoplastic lymphocytes, and that TA‐p63 mRNA expression correlated significantly (r = 0.9194, p < 0.0001) with the prevalence of p63 immunoreactivity. FISH extra signals for the p63 gene were found in seven (23.3%) of the 30 cases analysed (0/6 grade I, 2/15 grade II and 5/9 grade III; p = 0.01937). Further hybridizations showed a pattern highly suggestive of chromosome 3 polysomy in six cases. One of these cases also bore extra copies of the p63 and bcl‐6 genes. Co‐localization of p63 and IgH signals was found in one case. No association between the prevalence of p63 immunoreactivity and extra p63 gene signals was detectable when the cases were dichotomized according to a p63 immunoreactivity threshold of 10%. Our data suggest that TA‐p63 is overexpressed in high‐grade FL, possibly independent of the occurrence of gene abnormalities, and that it may be involved in the highly complex mechanism of regulation of apoptosis of FL cells. Copyright

Topoisomerase IIα gene status and prediction of pathological complete remission after anthracycline-based neoadjuvant chemotherapy in endocrine non-responsive Her2/neu-positive breast cancer

PURPOSE Topoisomerase IIalpha (Topo II) is a potential marker of responsiveness to anthracycline-based therapy. We analyzed the role of Topo II gene status in the prediction of pathological complete remission (pCR) after primary anthracycline-based chemotherapy in non- endocrine responsive breast cancers overexpressing Her2/neu. METHODS Twenty-three patients, with T2-T4, ER and PgR absent, overexpressing Her2/neu breast cancers treated with anthracycline-based chemotherapy were evaluated. Topo II gene status was assessed by FISH in pre-treatment tumor specimens and the results were correlated to pathological and clinical responses. RESULTS Overall, six patients had a pCR (26%). Topo II was amplified in 5 (22%) of the tumors. In all patients with Topo II amplification, Her2/neu gene amplification was also detected. Among patients without amplification, one had polysomia of chromosome (Cr) 17 and four patients had deletion of the Topo II gene. A higher probability of pCR was observed when Topo II amplification and Cr 17 polysomy were present: pCR was reported in 3 of 5 amplified tumors (60%), in the polysomic tumor (amplified plus polysomic 67%) and in only 2 out of 13 tumors without alteration of Topo II status (15%). If we compare the frequency of pCR in tumors with amplification or polysomy versus the frequency of tumors with not amplification (deletion or no modification), a significant difference was detected (p=0.02). One progressive disease (PD) was reported in one tumor with Topo II deletion (1/4, 25%) and one in tumor without any modification of Topo II gene status (1/13, 8%). CONCLUSIONS In patients with endocrine unresponsive and Her2 overexpressing tumors, Topo II amplification or the presence of chromosome 17 polysomy correlate with a significantly high probability of achieving pCR after neoadjuvant, anthracycline-based chemotherapy. Further prospective studies in order to more clearly define the predictive role of Topo II status in this subgroup of patients are warranted.

Retrospective Evaluation of Clinical Outcomes in Patients with HER2-Positive Advanced Breast Cancer Progressing on Trastuzumab-Based Therapy in the Pre-Lapatinib Era

BACKGROUND Patients with HER2-positive breast cancer whose disease has become resistant to the anti-HER2 monoclonal antibody trastuzumab can benefit from lapatinib, a dual epidermal growth factor receptor/HER2 tyrosine kinase (TK) inhibitor. Before the availability of this compound, trastuzumab was often continued beyond disease progression, usually in addition to further chemotherapy, an approach which was not based on randomized studies. We sought to retrospectively compare the clinical outcomes of patients who, upon progression during an initial trastuzumab-based regimen, stopped or continued trastuzumab in addition to further chemotherapy. PATIENTS AND METHODS From the clinical records of 407 patients with HER2-positive advanced breast cancer, we identified 279 patients progressing during an initial trastuzumab-based treatment. Of these patients, 83 continued trastuzumab in addition to chemotherapy, and 112 received chemotherapy alone. RESULTS We found no difference in response rate (28% vs. 30%; P = .5), median time to second tumor progression (8.4 months vs. 7 months; P = .24), or median postprogression survival (20.6 months and 15.4 months; P = .29) according to whether patients continued or stopped trastuzumab. At multivariate analysis, continuation of trastuzumab was associated with a statistically insignificant trend toward reduced risk of second progression (hazard ratio, 0.753; P = .08). CONCLUSION Patients with HER2-positive advanced breast cancer developing tumor progression during an initial trastuzumab-based regimen did not seem to benefit significantly from the continuation of trastuzumab in addition to chemotherapy. For these patients, there is evidence from a large randomized trial that effective HER2 targeting can be accomplished by inhibiting the HER2 TK activity with lapatinib.

Cyclin D3 immunoreactivity in follicular lymphoma is independent of the t(6;14)(p21.1;q32.3) translocation or cyclin D3 gene amplification and is correlated with histologic grade and Ki‐67 labeling index

An abnormal expression of cyclin D3, a key regulator of the cell cycle, has been documented in a variety of human malignancies, and the cyclin D3 gene, mapping to 6p21, may be deregulated in plasma cell myeloma and non‐Hodgkins lymphoma as a result of the t(6;14)(p21.1;q32.3) translocation and/or gene amplification. In the current study, we for the first time investigated by immunohistochemistry and fluorescence in situ hybridization (FISH) the prevalence of cyclin D3 abnormalities in follicular lymphomas (FLs), comparing the results with traditional clinicopathologic characteristics, p27 and skp2 immunoreactivity (IR) and Ki‐67 labeling index (LI). Cyclin D3, skp2 and Ki‐67 IR significantly increased from grade I to grade III FL (p = 0.0003, p = 0.0001 and p < 0.0001, respectively), while p27 IR was significantly (p < 0.0001) more prevalent in low‐grade tumors. Cyclin D3 IR was directly correlated with the Ki‐67 LI (p < 0.0001) and inversely correlated with p27 IR (p = 0.050). None of the 13 cases analyzed by FISH showed the t(6;14) translocation, but in 2 (15.3%) grade I FLs 3 cyclin D3 signals were detected. Cohybridization with probes specific for the centromeric region and the long arm of the chromosome 6 indicated trisomy in one case and a pattern highly suggestive for the presence of an isochromosome 6p in the other case. Our data suggest that the t(6;14) translocation may be extremely uncommon in FL and that a deregulated expression of cyclin D3, possibly due to epigenetic mechanisms, may be involved in the pathogenesis of high‐grade tumors.

Immunoreactivity for cyclin D3 is frequently detectable in high-grade primary gastric lymphomas in the absence of the t(6;14)(p21.1;q32.3) chromosomal translocation

Cyclin D3 plays a pivotal role in controlling the physiological progression from the G1 to the S phase of the cell cycle. Recent data suggest that cyclin D3 may be deregulated in extranodal non‐Hodgkins lymphomas (NHLs) as a consequence of the t(6;14)(p21.1;q32.3) translocation. The present study investigated for the first time by dual‐colour fluorescence in situ hybridization (FISH) on interphase nuclei and immunohistochemistry the prevalence of the t(6;14) translocation and cyclin D3 immunoreactivity (IR) in a series of 29 stage I–IIE primary gastric NHLs (PGLs). No case showed the t(6;14) translocation. However, in five (17.2%) cases (two extranodal marginal zone lymphomas of MALT type, LGM; one diffuse large‐cell lymphoma with a MALT component, DLCLM; and two diffuse large‐cell lymphomas without a MALT component, DLCL), three to four cyclin D3 signals were detected by FISH. Co‐hybridization with probes specific for the centromeric region and long arm of chromosome 6 indicated trisomy in one case (DLCL), whereas in the remaining four cases the pattern was highly suggestive of the presence of an isochromosome 6p. One (12.5%) case of LGM, six (75%) cases of DLCLM, and seven (53.8%) cases of DLCL (p = 0.0378) were immunoreactive for cyclin D3. Cyclin D3 IR was detected in two (40%) of the five cases with extra cyclin D3 signals and in 12 of the remaining 24 cases (50%, p = 1.000). These results suggest that the t(6;14) may represent a rare event in the pathogenesis of PGL and that cyclin D3 deregulation is most likely the result of epigenetic mechanisms. Copyright