Ki67 expression in breast cancer

ناطرس ىضرم يف Ki67 ةغبصل يعانلما روهظلا طنم مييقت :فادهلأا .Ki67 ل ةنكمم ةينهكت وأ ةيؤبنت ةميق يأ صحفو تايدوعسلا يدثلا Ki67 رشؤلم يمك مييقت فدهب تممص ةيداعتسا ةسارد هذه :ةقيرطلا ةيدوعس ةضيرم 115 نم يدثلا ماروأ تانيع يف يرثاكتلا )Ki67 PI( كللما ىفشتسم ،ىجولوثابلا مسقب 2015 سرامو رياني ينب تصخشُ ينب ةقلاعلا تطبرو .ةيدوعسلا ةيبرعلا ةكلملما ،ةرونلما ةنيدلما ،دهف ،ةيعانلما تاغبصلل ةكرتشلماو ةيدرفلا جئاتنلا عم )Ki67 PI( جئاتن ىف ةيضرلما ةيكينيلكلاا لماوعلا كلذكو ER ،PR ،)HER2(/neu .تلاالحا هذه ةضيرم 85 يف يلاع حوضوب Ki67 يعانلما طاشنلا رهظ :جئاتنلا ةيضرلما ةيكينيلكلإا لماوعلا عم )Ki67 PI( طبترإو ،73.9% ةبسنب ماروأ روهظو مرولا ةجرد عافتراو ةضيرلما نس مدقتك ؤبنتلا ةئيسلا Her-2/neu ةغبص ةيباجيإ ةدايز كلذكو ةيوافميللا دقعلا يف ةيوناث دقو .يلاوتلا ىلع )p<0.02, p<0.01, p<0.001, p<0.009( ميقب A ةيعرفلا مارولأا نم 62.9% يف )Ki67 PI( عافترإ نع فشكلا تم B ةيعرفلا مارولأا نم 84.4%و ةيدعاقلا ةيعرفلاا مارولأا نم 76.1%و عاونلأا عم رثؤم لكشب طبترا امك .Her-2 ةيعرفلا مارولأا نم 100%و Her-2/neu ةيباجيإ ىلع تلمتشا يتلا يدثلا ناطرسل ةيئيزلجا ةيعرفلا A ةيعرفلا مارولأاب ةنراقم Her-2 ةيعرفلا مارولأاو B ةيعرفلا مارولأا لثم .)p<0.04( ةميقب روهظلا بلاس Her-2/neu اهب ىتلاو يدثلا ناطرس تاضيرم ىدل Ki67 يرثاكتلا رشؤلما نأ دجوُ :ةتمالخا رهظ امك .اًيلماع هرشن تم اميف لجس ابم ةنراقم ريثكب ىلعأ تايدوعسلا Her-2 ةيعرفلا ةيئيزلجا يدثلا ناطرس عاونأ يف تناك هل ةبسن ىلعأ نأ ةكراشلماب Ki67 يرثاكتلا رشؤلما مادختسا نكيم هنأ دجوُو .B ةيعرفلاو ناطرس تاضيرم جلاع ةرادإ يف ةليسوك ىرخلأا نهكتلا تارشؤم عم يف ةينيتور ةروصب )Ki67 PI( مادختسا يغبنيو .تايدوعسلا يدثلا .مارولأاو ةجسنلأا تاربتخم يف يدثلا ماروأ صحف Objectives: To evaluate Ki67 immunoexpression pattern in Saudi breast cancer )BC( patients and investigate any possible predictive or prognostic value for Ki67. Methods: This is a retrospective study designed to quantitatively assess the Ki67 proliferative index )PI( in retrieved paraffin blocks of 115 Saudi BC patients diagnosed between January 2005 and March 2015 at the Department of Pathology, King Fahd Hospital, Al Madinah Al Munawarah, Kingdom of Saudi Arabia. The Ki67 PI was correlated with individual and combined immunoprofile data of estrogen receptor )ER(, progesterone receptor )PR(, and human epidermal growth factor receptor 2 )HER2/neu( with their clinicopathological parameters. Results: Ki67 immunoreactivity was highly expressed )>25% of the tumor cells were positive( in 85 )73.9%( patients. The Ki67 PI was significantly associated with poor prognostic clinicopathological parameters including old age )p<0.02(, high tumor grade )p<0.01(, lymph node metastasis )p<0.001(, and Her-2/neu positivity )p<0.009(. However, the association with ER positivity, PR positivity, tumor size, and lymphovascular invasion were not statistically significant. The Ki67 PI was significantly associated with BC molecular subtypes that were Her2/neu positive )luminal B and HER-2( subtypes compared with the Her2/neu negative )luminal A( subtype )p<0.04(. Conclusion: The Ki67 PI is significantly higher in Saudi BC patients comparing with the reported literature. Ki67 PI was highest in the HER-2 and luminal-B molecular subtypes. Along with other prognostic indicators, Ki67 PI may be useful in predicting prognosis and management of Saudi BC patients. Saudi Med J 2016; Vol. 37 (2): 137-141 doi: 10.15537/smj.2016.2.12285 From the Department of Pathology (Elkablawy, Albasri, Mohammed, Hussainy, Nouh), Faculty of Medicine, Taibah University, the Department of Pathology (Alhujaily), King Fahd Hospital, Al Madinah Al Munawarah, Kingdom of Saudi Arabia, the Department of Pathology (Elkablawy, Faculty of Medicine, Menoufia University, Menoufia, the Department of Pathology (Mohammed), Faculty of Medicine, Asiut University, Assiut, and the Department of Pathology (Nouh), Faculty of Medicine, Benha University, Benha, Egypt. Received 24th May 2015. Accepted 9th December 2015. Address correspondence and reprint request to: Dr. Mohamed A. Elkablawy, Assistant Professor, Department of Pathology, Faculty of Medicine, Taibah University, Al Madinah Al Munawarah, Kingdom of Saudi Arabia. E-mail: [email protected] OPEN ACCESS 137 www.smj.org.sa Saudi Med J 2016; Vol. 37 )2( Original Articles Ki67 expression in BC Saudi patients ... Elkablawy et al 138 Saudi Med J 2016; Vol. 37 )2( www.smj.org.sa B cancer )BC( is one of the most common malignancy in the world.1 Although in the Kingdom of Saudi Arabia )KSA(, the incidence of BC is much lower than in the Western world; it is still the most common malignancy in the Saudi women. According to the Saudi Cancer registry,2 BC accounted for approximately 23% of all the newly diagnosed female cancers. An additional significant fact on BC in KSA is its special presentation; as it predominantly affects the younger population, frequently presents as higher histological grades and in advanced clinical stages.2-4 Apart from the problem of its being highly prevalent globally and locally; BC has also shown its divergent nature with regards to its clinical course, response to treatment, and prognostic outcomes. Thus, the new molecular classification of BC has emerged on the basis of biomarkers. In the initial stages, the hormones namely, the estrogen receptor )ER(, progesterone receptor )PR(, and human epidermal growth factor receptor 2 )Her2( played their roles. It was only 15 years ago, that the molecular classification of BC was proposed by Californian scientists, initially there were 4 major classes: luminal-like, basal-like, normal-like, and Her2 positive.5 Consequently, a fifth class was added, dividing one of the major luminal class to luminal A and luminal B classes.6-8 Ki67 had been known to be an important proliferation biomarker since 1980s. It has recently become an essential component of routine biomarker profile for BC, along with ER, PR ,and Her2, to assist the oncologists in delivering optimum treatment to BC patients. Its role as a poor prognostic biomarker is well established, and a number of studies have found a significant correlation between Ki67 positivity with that of histological parameters such as nuclear grades and mitotic figures.9 Recent studies have also proved its predictive role in both the antihormonal therapy and chemotherapy for the efficacy of the treatment. The aim of this study is to examine the Ki67 biomarker in the BC patients and the immunohistochemically on the paraffin embedded blocks. Subsequently, to correlate the Ki67 findings with individual and combined immunoprofile data of ER, PR, and Her2/neu, as well as with their clinicopathological parameters to identify any specific differences in our BC cases as compared with western cases. This is may be important in investigating any predictive or prognostic role of Ki67 in managing BC patients in KSA population. Methods. Patient’s tissue and data collection. A total of 115 patients with invasive BC diagnosed between January 2005 and March 2015 at the Department of Pathology, Al Madinah Al Munawarah, KSA were included in this study. Each case was reviewed by 2 authors and histologically graded with regard to a number of features )Table 1). Clinicopathological parameters, including age at diagnosis, tumor type, size, lymph node, and lymphovascular status were all available. Histologic grade was assessed by Modified Bloom-Richardson System )MBR(. Only histopathologically confirmed invasive carcinoma cases were included. In-situ lesions, recurrences, biopsies, sarcomas, benign lesions, and metastases were excluded. Modified radical mastectomies, quadrectomy, and wide local excision specimens were included. This study was approved for publication by the Pathology Department, King Fahad Hospital, Al Madinah Al Munawarah, KSA. Molecular subtypes of breast cancer. The BC were classified into 4 subtypes as follows: luminal A )ER+, PR+/-, Her2/neu -(, luminal B )ER+, PR+/-, Her2/neu +(, Her2 )ER-, PR-, Her2/neu +(, and basal-like )ER-, PR-, Her2-/neu-( according to Onitilo et al10 )Table 1(. Ki67 immunohistochemical (IHC) staining. Tissue cores were extracted from archival blocks of the primary BC and used to construct a tissue miniarray )TmA( as previously described.11 To overcome the problem of BC heterogeneity during measurement of Ki67 proliferative index )PI(, 2 representative cancerous foci were marked on slides with hematoxylin and eosin-stained sections from the selected paraffin blocks. Two tissue cores )each of 2 mm( were used to create TmAs from each block. In most TmA modules, it is recommended to obtain at least 2 cores per tumor to improve its reliability.12 Immunohistochemical staining of Ki-67 was performed at room temperature and washes were performed with tris-buffered saline. A 4 μm slices of formalin-fixed paraffin-embedded TmA were dewaxed and rehydrated. Antigen retrieval was carried out using EDTA retrieval solution PH 9 in a standard microwave oven for 10 minutes. Endogenous peroxidase activity was blocked with 3% hydrogen peroxide )S2023, Dako, Glostrup, Denmark(. Sections were then incubated with primary antibodies against Ki67 )MIB-1, 1:100, Dako, Glostrup, Denmark( for 32 minutes at 42°C according to the manufacturer’s instructions. The signals were visualized with diaminobenzidine )K3468, Dako, Glostrup, Denmark( for 10 minutes, and were counterstained with hematoxylin. Scoring of Ki67 immunostaining. The nuclear immunostaining of Ki67 was assessed by counting at Disclosure. Authors have no conflict of interest, and the work was not supported or funded by any drug company. Ki67 expression in BC Saudi patients ... Elkablawy et al 139 www.smj.org.sa Saudi Med J 2016; Vol. 37 )2( least 500 tumor cells per case across 5 high power fields of the section under microscope. The Ki67 PI was scored as high when >25% of the tumor cells were positive; and low when <25% cells were positive )Figure 1(. The immunostained slides were evaluated independently. Statistical analyses. Data were statistically analyzed using the Statistical Package for Social Sciences Version 22.0 for Windows )IBMCorp, Armonk, NY, USA(. Interobserver reproducibility was assessed by correlation analysis between the 2 data sets. Association between the Ki67 PI and patient clinicopathological parameters was determined using the Chi-squared test and Fisher’s exact test. For all statistical analyses, a p-value of ≤0.05 was considered significant. Results. The clinicopathological characteristics of 115 female BC patients are shown in Table 1. The mean age was 50 years )range: 26-88 years(. The pathological examination showed invasive ductal carcinoma, not otherwise specified in 109 )94.9%( cases, infiltrating lobular carcinoma, mucinous carcinoma, and metaplastic carcinoma in 2 )1.7%( cases each. Tumor grades distribution was grade I, grade II, and grade III. Tumor size distribution was T1 )15.6%(; T2 )74%(, and T3 )10.4%(. Seventy-seven cases )67%( had positive lymph nodes and 83 cases )72.2%( had lymphovascular