Nirmala Pathmanathan

Ki67 and proliferation in breast cancer.

New approaches to the prognostic assessment of breast cancer have come from molecular profiling studies. A major feature of this work has been to emphasise the importance of cancer cell proliferation as a key discriminative indicator of recurrence risk for oestrogen receptor positive breast cancer in particular. Mitotic count scoring, as a component of histopathological grade, has long formed part of a routine evaluation of breast cancer biology. However, there is an increasingly compelling case to include a specific proliferation score in breast cancer pathology reports based on expression of the cell cycle regulated protein Ki67. Immunohistochemical staining for Ki67 is a widely available and economical test with good tolerance of pre-analytical variations and staining conditions. However, there is currently no evidence based protocol established to derive a reliable and informative Ki67 score for routine clinical use. In this circumstance, pathologists must establish a standardised framework for scoring Ki67 and communicating results to a multidisciplinary team.

The prognostic value of Ki67 in systemically untreated patients with node-negative breast cancer

Aim To evaluate the utility of Ki67 as a prognostic marker in a series of patients with node-negative breast cancer untreated with adjuvant systemic therapy. Methods The cohort consisted of 203 cases treated with breast conserving surgery and radiation only; median follow-up was 183 months (range 156–277 months). An immunohistochemical panel of oestrogen receptor (ER), progesterone receptor (PR), cytokeratin (CK)5/6 and Ki67 and human epidermal growth factor 2 in situ hybridization (HER2-ISH) was performed on the tumour samples. Ki67 scores were evaluable in 193/203 patients (95.1%). The primary outcome was breast cancer specific survival (BCSS). Results Of the cohort, 29 (14.2%) died of breast cancer. A cut off of 10% separated tumours into a ‘Ki67-low’ (n=70) or ‘Ki67-high’ group (n=123). The breast cancer specific survival was 97.1% and 77.6% for Ki67-low and Ki67-high groups, respectively. Univariate analysis showed that in this lymph node-negative cohort, the predictors for BCSS were tumour size, Ki67, LVI, age and histological grade 3. Multivariable analysis showed that Ki67 index and lymphovascular space invasion were independent predictors of breast cancer death. To examine the utility of Ki67 in assignment of immunohistochemically molecular subtypes, cases were assigned into Luminal A (ER-positive, HER2-negative, Ki67 ≤14%), Luminal B (ER-positive, HER2-negative, Ki67 >14%) and triple negative (ER/PR-negative and HER2-negative, any Ki67). The 15-year breast cancer specific survival was 91.7%, 79.4% and 75.8%, respectively. Conclusions A statistically significant difference in breast cancer specific survival is seen in groups defined using Ki67 and receptor status, whereas histological grading was not a significant predictor of survival. Ki67 immunostaining provides prognostic information beyond traditionally assessed clinicopathological variables.

Characteristics of HER2-positive breast cancer diagnosed following the introduction of universal HER2 testing

The aim of this study was to determine the impact of universal HER2 testing on the clinico-pathologic profile of HER2+ breast cancer. Data were extracted from breast cancer pathology reports spanning two periods: before (2003/4, n = 379), and after (2008/9, n = 560) the introduction of universal testing. In 2003/4, 43.3% of breast cancers were tested for HER2 with 16% of tested cases HER2+. In 2008/9, 98.4% of cases were tested with 14.7% HER2+. In 2008/9, HER2+ status was associated with younger age, higher grade, increased tumour size, lymph node involvement, negative oestrogen and/or progesterone receptor status. HER2+ cases diagnosed in 2003/4 were not significantly different in respect of these features. The rate of HER2+ breast cancer amongst screen detected cases in 2008/9 was 8.3%. The phenotype of HER2+ breast cancer was stable following the introduction of universal testing. The overall rate of HER2+ breast cancer was influenced by screen detection.

Intraoperative sentinel lymph node assessment in breast cancer: a comparison of rapid diagnostic method based on CK19 mRNA expression and imprint cytology

Sentinel lymph node biopsy in breast cancer is a routine technique for staging the axilla. The two most common methods of intraoperative histopathological assessment, imprint cytology and frozen section, are hampered by poor sensitivity and lack standardized methodology. The one‐step nuclei acid amplification (OSNA) assay is a rapid quantification of cytokeratin 19 mRNA. This prospective study compared an existing intraoperative imprint cytology protocol with the OSNA system.

HER2 testing in breast cancer: an overview of current techniques and recent developments

Summary Testing for HER2 positivity in breast cancer carries implications for prognosis and therapeutic response in patients. In recent times there have been numerous developments and refinements in the available technologies for HER2 testing. In addition to this, guidelines have been developed and modified in an attempt to improve reliability and accuracy of testing. Immunohistochemistry and FISH testing have been the most widely used methodology, and the technique which has the largest knowledge base. Some of the inherent disadvantages have prompted the development of newer brightfield techniques which overcome some of these issues. There is gathering experience with these emerging technologies. Despite efforts to optimise and standardise procedures there remains a small percentage of cases that continue to be unresolved, whether this be due to issues of polysomy of chromosome 17, other complex genetic changes or analytical/interpretative issues. An ideal method for the resolution of these equivocal results should be considered in a specialised testing/referral centre, and this may include karyotyping studies of chromosome 17 or multiple probes for chromosome 17 using fluorescence in situ hybridisation or multiplex ligation-dependent probe amplification. It is timely to review of some of the newer techniques available for routine testing and approaches for cases which prove difficult to resolve using conventional testing methodology.

Diagnostic evaluation of papillary lesions of the breast on core biopsy

The management of asymptomatic intraductal papillary lesions of the breast diagnosed on core biopsy poses a challenge for patients and clinicians, as the distinction between common benign lesions and atypical or malignant varieties may be difficult without formal excision. The aim of this study was to determine whether a combination of histopathologic and biomarker features could be used to accurately identify benign papillary lesions on core biopsy. An inclusive group of 127 excised papillary lesions was characterized by detailed histopathologic review and immunohistochemical staining for the basal markers cytokeratin 5/6 (CK5/6) and P63 and the proliferation marker Ki67. Comparison of benign, atypical, and malignant lesions revealed that the combination of broad, sclerotic fibrovascular cores, and epithelial CK5/6 staining was most commonly seen in benign papillomas. Ki67 staining revealed striking intralesional heterogeneity, but there was no difference between the high scores of benign, atypical, or malignant lesions (P=0.173). In a non-overlapping set of 42 cases, a binary classifier specifying benign lesions on the basis of thick fibrovascular cores and epithelial CK5/6 staining on core biopsy gave an overall misclassification rate of 4/42 (10%) when compared with the final excision diagnosis. Misclassified cases included 2/27 lesions ultimately diagnosed as benign and 2/2 atypical papillomas. All malignant lesions (n=13) were correctly assigned. The combined assessment of fibrovascular core thickness and CK5/6 staining on core biopsy distinguished benign from malignant papillary lesions, but did not separate benign from atypical cases. This approach may form a useful addition to the clinicopathologic evaluation of papillary lesions of the breast.

Intraoperative imprint cytology of sentinel lymph nodes in breast cancer: initial experience and lessons learnt in establishing a new practice

Aims: The initial 18 months experience of performing intraoperative imprint cytology for patients with breast cancer undergoing sentinel lymph node biopsy is described for a single institution. The learning process is compared with published results from institutions with many years of experience in order to assess progress in reaching those ideal results, and the methodology used by these institutions is reviewed. Methods: A retrospective review was undertaken of the intraoperative imprint cytology results from 103 patients with breast cancer (yielding a total of 170 lymph nodes) who underwent imprint cytology of their sentinel lymph node. The intraoperative imprint cytology results were compared with the final histopathological results. Details regarding the primary tumour characteristics and metastatic deposit size were recorded. Results: The sensitivity for imprint cytology was 31.1%, with a specificity of 100% and overall accuracy of 77.8%. The sensitivity for detecting macrometastases (>2 mm diameter) was 61.9% and the sensitivity for micrometastases (<2 mm diameter) and including isolated tumour cells was 4.2%. Conclusions: The differences in sensitivity in comparison with many studies in the literature are multifactorial, and include technical aspects, such as the methodology used in the final histopathological and intraoperative evaluation of the sentinel lymph nodes, interpretative difficulties, and much lower case numbers. Furthermore, these numbers represent early experience and methods to improve sensitivity and overall accuracy are detailed in this paper.

A thermochromic dispersive electrode can measure the underlying skin temperature and prevent burns during radiofrequency ablation.

Introduction: Burns at the dispersive electrode are serious complications of diathermy and radiofrequency (RF) ablation procedures. We aimed to create a new methodology to reduce the incidence of dispersive electrode related skin burns. We hypothesized that a dispersive electrode incorporating a thermochromic liquid crystal (TLC) layer could accurately measure underlying skin temperatures and help prevent burns.

Familial concordance of breast cancer pathology as an indicator of genotype in multiple-case families.

The heterogeneity of multiple case breast cancer families that do not carry mutations in BRCA1 or BRCA2 (non‐BRCA1/2 families) poses a challenge to the identification of breast cancer susceptibility genes. The aim of this study was to determine whether intrafamilial concordance in breast cancer pathology could identify subgroups of non‐BRCA1/2 families with consistent genotypic features. Invasive breast cancers were reviewed from 84 individuals belonging to 30 multiple‐case families; BRCA1 (n = 9), BRCA2 (n = 10), and non‐BRCA1/2 (n = 11). Hierarchical cluster analysis based on histopathology and age at first diagnosis was then used to specify three subgroups designated Clusters 1–3. The genomic features of non‐BRCA1/2 families were examined by genome wide linkage and FGFR2 SNP genotyping, according to whether they showed cluster‐concordant or cluster‐mixed familial pathology. The majority of pathogenic BRCA1 mutation carriers (80%) fell into a single cluster. In contrast pathogenic BRCA2 mutation carriers were distributed across all three clusters and within families, cluster groups were also generally mixed. Most non‐BRCA1/2 mutation carriers belonged to Cluster 3 (71%). Genome wide linkage data from five non‐BRCA1/2 Cluster 3‐concordant families were compared with four mixed cluster non‐BRCA1/2 families. This revealed a number of distinct linkage peaks, including some regions previously associated with breast cancer susceptibility. The distribution of low risk alleles in FGFR2 was not different between these two subgroups (P = 0.237). The pattern of breast cancer pathology concordance amongst family members may assist the investigation of breast cancer susceptibility in multiple case families.

Composite phaeochromocytoma with intratumoural metastatic squamous cell carcinoma

Sir, Composite phaeochromocytomas are unusual variants of phaeochromocytoma. The case presented here is particularly unusual in that it showed an intratumoural deposit of metastatic squamous cell carcinoma within a composite phaeochromocytoma. To our knowledge, such a combination has not previously been reported in the literature. A 73-year-old male with a background history of heavy smoking, coal worker’s pneumoconiosis, ischaemic heart disease and hypercholesterolaemia, initially presented with abdominal pain. CT scans revealed a mass in the left lower lobe of the lung and a left adrenal mass. Biopsies of the lung mass and subsequent lobectomy showed poorly differentiated squamous cell carcinoma. Two months later, the patient presented with syncopal episodes and labile blood pressure. Further investigations revealed an increase in urinary catecholamines. A clinical diagnosis of phaeochromocytoma was made and laparoscopic adrenalectomy was performed. Macroscopically, the adrenal gland was partly replaced by a tumour mass measuring 65658645mm. The residual adrenal gland tissue measured 3061062mm. The total weight of the specimen was 102 g. The capsule was focally disrupted. The cut surface of the tumour was soft and grey-brown in colour with yellow necrotic areas and cystic spaces. Microscopically, the tumour was highly vascular and there were extensive areas of fresh haemorrhage and tumour necrosis. Some areas of the tumour showed typical features of phaeochromocytoma, with a trabecular and alveolar growth pattern (Fig. 1); in these areas, the cells had indistinct granular and eosinophilic cytoplasm, and large, vesicular nuclei. Focally, mainly at the periphery of the lesion, the cells had a spindled appearance. Other areas of the tumour showed ganglioneuroblastoma, composed of large nests of cells with small, round and hyperchromatic nuclei, separated by a fibrillary neuropil-like stroma; scattered ganglion-like cells were present in these areas (Fig. 2). The tumour was confined within the adrenal