Improvements in undergraduate oncology education introduced at Polish medical universities between 2004 and 2010 under Poland's "National Program for Combating Neoplastic Diseases".

Cancer patient treatment in Poland remains unsatisfactory when compared to that in other countries. In 2005, this alarming situation prompted the Polish government to launch the "National Program for Combating Neoplastic Diseases" (NPCND). One part of this project was to improve the quality of oncology instruction at the undergraduate level over the years 2006 and 2007 (subsequently extended until 2010 thanks to promising results and the relatively small financial outlay). The program's main aims were to improve existing oncology therapy and to ameliorate the quality of undergraduate oncology education. To evaluate the changes in the quality of undergraduate education as a result of the NPCND program, medical universities were asked to fill out a questionnaire. Responses indicate that the program had a major positive impact on the quality of cancer education mainly as a result of the introduction of a uniform program of training and an increase in the number of classes devoted to oncology. The main unresolved problem is that university hospitals seldom have integrated units catering in-house for surgery, radiotherapy, chemotherapy, etc., and most such "hands-on" teaching still has to be done externally.

Matrix metalloproteinase (MMP)-2 and MMP-9 expression in tumor infiltrating CD3 lymphocytes from women with endometrial cancer.

OBJECTIVE: In this study, we hypothesized that not only endothelial malignant cells but also lymphocytes infiltrating tumor epithelium, in patients with endometrial cancer, could be an important source of the gelatinases (matrix metalloproteinase [MMP]-2 and MMP-9) extensive production, which in turn, may facilitate tumor cells infiltration and progression due to the extracellular matrix degradation. MATERIALS AND METHODS: First, we isolated lymphocytes from the endometrial carcinoma samples taken from 41 patients who were operated on and from healthy endometrial tissue taken of the same patients after histological verification. Then, we detected the level of CD3-positive cells in endometrial tissues by flow cytometry. Simultaneously, we studied the messenger RNA expression of MMP-2 and MMP-9 in the isolated cells from malignant and unchanged endometrial tissues. Using immunohistochemistry, we compared the protein expression of MMP-2, MMP-9, and CD3 in the studied samples. RESULTS: We showed the enhanced abundance of CD3 lymphocytes both by flow cytometry and immunohistochemistry in the samples from malignant tissues. The expression of MMP-9 in the endometrial carcinoma was increased significantly at the protein level but not at the messenger RNA level. We could not observe any differences concerning MMP-2 expression in both methods of detection. CONCLUSIONS: CD-3 lymphocytes significantly infiltrate endometrial cancer tissue, but they do not seem to be the source of enhanced metalloproteinases 2 and 9 expression in the tumor environment. Still, owing to the immunohistochemistry staining, we could show the significant increase of MMP-9 protein in the very close vicinity of tumor-infiltrating CD3 lymphocytes. Could it be the result of CD3 lymphocyte action, or is it just the imperfection of the detecting method we used? This remains unclear. Further studies explaining the role of tumor infiltrating lymphocytes in mediating the endometrial cancer milieu are needed.

Urinary complications in rectal cancer patients are related to the dissection tool.

BACKGROUND/AIMS: To assess the incidence and risk of urinary complications after anterior rectal cancer resection with regard to the surgical device used for total mesorectal excision (TME). METHODOLOGY: During the years 2004-2009 we operated 374 rectal cancer patients with TME and the intent of autonomic nerves sparing intent. Seventeen patients underwent mesorectal dissection with ultrasound scalpel (US). They were compared to the control series of 35 cases selected from the patients for whom electrocautery was used. Selection was done in the manner to eliminate any other significant differences between groups. RESULTS: Intraoperative complications, postoperative mortality, anastomotic leakage and infectious complications did not occur. Urinary bladder disturbances developed in US group in 1 patient (6%) while in 12 patients (34%) in EC group (p<0.05). In US group the character of complication was transient stress incontinence with symptoms being significantly reduced during six postoperative months. In EC group two patients had dysuria, two nycturia, one had both. Stress incontinence occurred in six patients, complete incontinence requiring catheterization in one. CONCLUSIONS: When compared to EC, TME with US is related to lower risk of urinary complications and facilitates autonomic nerve preservation due to minimized thermal lateral tissue damage.

Prognostic role of c-met expression in breast cancer patients.

BACKGROUND: Hepatocyte growth factor plays an important role in tumor growth, metastasis and angiogenesis. C-met is HGF's high affinity receptor. AIM: The aim of the study was to assess the correlations between c-met expression and clinic-pathological factors in breast cancer tissues. Furthermore, the purpose of the study was to evaluate the prognostic value of the hepatocyte growth factor receptor (HGFR, c-met) expressions in homogenous group of breast cancer patients. MATERIALS AND METHODS: Tumor samples were collected from 302 patients with breast carcinoma treated with primary surgery. We have assessed the percentage of tumor cells with c-met expression, the intensity of reaction and the ratio of these two factors-immunoreactivity according to the Remmele score. RESULTS: We have observed no correlations between HGFR immunoreactivities and clinical parameters (tumor size, grade, axillary lymph node status, age). In 5-year observation we have found prognostic value of assessing c-met immunoreactivity in primary tumor. CONCLUSION: Our study has revealed prognostic value of c-met. Unlike in other authors' studies, our patients' group is very homogenous which might contribute to obtained results.

[The importance of determining the prognostic marker YKL-40 in serum and tissues]. / Znaczenie rokownicze oznaczania markera YKL-40 W surowicy i tkankach.

YKL-40 is detected in the early nineties not only a glycoprotein secreted by cancer cells, but also of neutrophils, chondrocytes and endothelial cells. Biological function of YKL-40 are not exactly known, it is suggested that this protein participates in many physiological and pathological processes such as proliferation, angiogenesis, mitogenesis and remodelling. It is also a factor antyapoptotic and growth factor for some cells. Increased levels of YKL-40 in serum have been described in many diseases running with inflammation such as rheumatoid arthritis, systemic lupus erythematosus and Crohn's disease, and also in the group of cardiovascular diseases. Determination of the concentration of serum YKL-40 was also used in oncology. The tumors at various sites were found elevated levels of this marker in serum, as well as overexpression in tumor tissue. It was observed that higher titers YKL-40 levels are associated with shorter overall survival and disease-free period. It is suggested that measuring the concentration of YKL-40 in serum and its expression in tumor tissues may serve as a valuable and independent prognostic factor.

Correlation of metallothionein expression with clinical progression of cancer in the oral cavity.

UNLABELLED: This study aimed at finding out whether the expression of metallothionein (MT), laminin, Ki-67 antigen and minichromosome maintenance-2 (Mcm-2) protein changes with growing invasiveness of the tumour. The expression of these markers in primary tumours with no metastases to lymph nodes (PT N-) was compared with the expression in primary tumours with metastases in draining lymph nodes (PT N+). The difference in marker expression was also evaluated between metastatic lymph nodes (LN+) and the corresponding primary tumours (PT N+). PATIENTS AND METHODS: The studies were performed on tumour samples from 39 patients with squamous cell carcinoma of the oral cavity floor or of the oral part of the tongue. All the patients had been subjected to radical surgery, accompanied by the removal of lymph nodes. In 20 patients post-operative histopathology disclosed the presence of metastases in the draining lymph nodes (pN+), while in 19 patients the presence of such metastases was excluded (pN0). RESULTS: The PT N+ group was found to contain a significantly higher percentage of cells with cytoplasmic expression of MT, than the PT N- group. In turn, a significant increase in the intensity of reaction of cytoplasmic MT and an increased percentage of cancer cells demonstrating MT expression in the cell nuclei was demonstrated in the LN+ compared to the PT N+ group. The expression of the remaining parameters did not significantly differ between PT N-, PT N+ and LN+. CONCLUSION: A gradual increase in MT expression (both cytoplasmic and nuclear) takes place with progression of the tumour and the increased nuclear expression of MT in LN+ cells may suggest a role of MT in metastasis development in the studied tumours.

Mastectomy approach with Y-shaped incision: a technique designed for women with obesity.

OBJECTIVE: To evaluate the access to axilla, postoperative complications, and cosmetic results of the modified radical mastectomy with a Y-shaped approach especially designed for women with obesity. METHODS: One hundred seventeen consecutive women with obesity with infiltrating breast cancer were studied. All of them were not eligible for breast-conserving therapy and underwent modified radical mastectomy. Operation was performed using a surgical technique designed to improve the axillary clearance and to eliminate the lateral dog ear deformity. Two oblique incisions were added to the traditional transverse Stewart incision at the lateral part forming the Y-shaped approach. After lateral flap retraction, the axillary dissection was done. Before closing the wound, the triangular flap was advanced medially, whereas superior and inferior areas of redundant skin overlying the latissimus dorsi muscle were excised. RESULTS: No intraoperative complications were observed. In each case, the axillary dissection (with level 3 node clearance when needed) was performed with ease. The wound was healed by primary adhesion, giving an excellent cosmetic result without lateral dog ear deformity. Skin flap necrosis was found in 2 elderly patients. Wound hematoma and surgical site infection developed in 1 patient each. Necrosis of the apex of axillary triangle occurred in one woman with diabetes. These rare complications were managed successfully in all the cases. CONCLUSIONS: The Y-shaped approach for modified radical mastectomy is a simple and safe technique. It facilitates the wide access to axilla and improves cosmesis in women with obesity by eliminating lateral dog ear deformity.

[The effectiveness of population-based breast cancer screening programme]. / Skutecznosc populacyjnego programu wczesnego wykrywania raka piersi.

UNLABELLED: Well-organised mammography screening programme can significantly reduce the breast cancer mortality However, changes in mortality rates take a long time thus some early indicators are usually used to monitor the effectiveness of the programme. If these operational objectives are accomplished then the programme can replicate the mortality reduction achieved in randomised trials. THE AIM OF THIS STUDY: To evaluate the quality of breast cancer screening programme in the region of Lower Silesia during the first year of its operating. MATERIAL AND METHODS: Centrally organised breast cancer screening has been introduced since the beginning of the year 2007. This population-based programme is designed for women aged 50-69. Females undergoing treatment or being followed-up due to breast cancer are not invited. Screen-film two-view mammography without clinical examination is used as a screening test which is to be performed every two years. The second level diagnostic tools are breast clinical examination and additional imaging (mammography and ultrasound). Following further assessment women are referred to the examination at the routine round length of the programme, at the less interval (short-term recall) or biopsy procedures. Quality assessment was done via early indicators according to the European guidelines. RESULTS: The attendance rate was 41% (79,143 women screened within 192,613 eligible population for one year). Technical repeat rate, further assessment rate, and short-term recall rate were: 0.26%, 6.85%, and 0.91%, respectively. Pathologically confirmed breast cancer was revealed in 364 women giving the detection rate 4.59 for 1000. Cancer detection rate to expected incidence ratio was 3.35. CONCLUSIONS: Mammography service performed during the first year of breast cancer screening programme in the region of Lower Silesia conforms to quality assessment parameters recommended by the European guidelines at the acceptable level. The main problem at the start of this programme is too low coverage. Invitation process must be strongly intensified to improve long-term effectiveness and to significantly reduce breast cancer mortality.

Clinical factors in prediction of prognosis after anterior resection with total mesorectal excision for carcinoma of the rectum.

The aim of the study was to estimate the long-term results and the prognostic value of clinical and pathological factors following R0 anterior resection with total mesorectal excision (TME). Ninety-eight consecutive patients with histologically confirmed rectal cancer were studied prospectively with five-year follow-up. Survival was calculated using the Kaplan-Meier method and differences between curves were tested by the log-rank test. Multivariate analysis was performed using the Cox regression model. Recurrence-free survival (RFS) was 63.6%. Mean time of recurrence was 13.8 months (range 3-38). Local recurrence rate was 7.8% with the mean time of 12.7 months (range 3-25). In univariate analysis Dukes' stage (RFS for stage: A=93.2%; B=53.8%; C=26.3%) and preoperative CEA serum level (s-CEA) (for s-CEA5 ng/ml RFS=5.9%) significantly influenced survival (P<0.005 and P<0.00001). These parameters were also found to be independent prognostic factors in multivariate analysis (P<0.05 and P<0.00001). Survival was worse in older female patients with low-localised poorly differentiated tumors; however, those variables had not significant impact on prognosis. Neither symptom duration nor mucinous histology was significantly related to survival. Using TME technique a low local recurrence rate resulting in improved survival can be achieved. Apart from clinicopathological staging, elevated s-CEA can identify patients with poor prognosis. In addition to TME adjuvant therapy for this high-risk group should be considered.

Evaluation of prognostic value of VEGF-C and VEGF-D in breast cancer--10 years follow-up analysis.

UNLABELLED: The aim of the study was to evaluate the prognostic value of vascular endothelial growth factor C (VEGF-C) and VEGF-D expression in stage II, grade 2 and 3, ductal breast cancer patients. PATIENTS AND METHODS: The immunohistochemical staining of 98 tumor samples and 5- and 10-year overall (OS) and disease-free survival (DFS) were analyzed. RESULTS: A significant relationship between VEGF-C and VEGF-D expression (p=0.000002) was noted. No correlations between protein expression and clinical parameters (tumor size, grade, estrogen receptor status, axillaty lymph node metastases and age) or 5- and 10-year DFS or OS were demonstrated. A close to significant correlation (p=0.084) was observed between high expression of VEGF-C and 5-year OS. CONCLUSION: Our study did not reveal any prognostic value of VEGF-C or VEGF-D. Therefore they are not useful as markers for patients with poor prognosis. Unlike in other studies, our patient group was homogenous which might have contributed to the results obtained.

Hepatitis C virus infection and locally advanced splenic marginal zone lymphoma.

Splenic marginal zone lymphoma (SMZL) is a rare malignant B-cell neoplasm, usually with an indolent clinical course and favorable prognosis. Treatment options include chemotherapy, surgery, radiation and immunotherapy. In some recent studies an increased incidence of hepatitis C virus (HCV) infection in patients with SMZL was reported and its possible role in lymphomagenesis was emphasized. A 66-year-old woman with twelve-year history of HCV infection was admitted due to locally advanced abdominal tumor involving the spleen and the left part of the diaphragm. Transaminase serum levels were not elevated. Neither peripheral lymphadenopathy nor bone marrow pathology was found. Absolute blood lymphocyte, erythrocyte and platelet counts were normal. A splenectomy with partial diaphragm resection in one block was performed. Recovery was uneventful. Pathologic examination with immunohistochemistry revealed SMZL and confirmed a neoplastic infiltration of the resected diaphragm. Following surgery, chemotherapy (CHOP regimen) and immunotherapy (anti-CD20 antibody) were given. At the last follow-up 15 months after surgery, the patient was free of any symptoms of lymphoma. Surgical resection of even locally advanced SMZL with involvement of adjacent tissues can be performed as a diagnostic and therapeutic procedure. Splenectomy is especially indicated in symptomatic patients without other sites of the disease. HCV infection may result in increased risk of SMZL due to the induction of B-cell lymphoproliferation. Because of possible lymphoma regression following anti-viral therapy, a systematic screening for HCV in patients with SMZL seems to be valuable and helpful for treatment planning.

Sphincter-preserving R0 total mesorectal excision with resection of internal genitalia combined with pre- or postoperative chemoradiation for T4 rectal cancer in females.

AIM: To evaluate the impact of chemoradiation admi-nistered pre- or postoperatively on prognosis in females following R0 extended resection with sphincter-preserving total mesorectal excision (TME) for locally advanced rectal cancer and to assess the association between chemoradiation and intra- and postoperative variables. METHODS: Twenty-one females were treated for locally advanced but preoperatively assessed as primarily resectable rectal cancer involving reproductive organs. Anterior resection with TME and excision of internal genitalia was combined with neo- or adjuvant chemoradiation. Two-year disease-free survival analysis was performed with the Kaplan-Meier method and log-rank test. The association between chemoradiation and other variables was evaluated with the Fisher's exact test and Mann-Whitney test. RESULTS: Survival rate decreased in anaemic females (51.5% vs 57.4%), in patients older than 60 years (41.8% vs 66.7%) with poorly differentiated cancers (50.0% vs 55.6%) and tumors locatedor=1 L, rate of postoperative bladder and anorectal dysfunction, and minimal distal resection margin. It significantly influenced minimal radial margin (mean 4.2 mm vs 1.1 mm; P<0.01). CONCLUSION: Despite involving internal genitalia, long-term disease-free survival and sphincter preservation may be achieved with combined-modality therapy for females with T4 locally advanced rectal carcinoma. Neoadjuvant chemoradiation does not compromise functional results and may significantly improve oncological outcomes probably due to enhanced radial clearance.

[The value of the cytocins and the solubility of theirs receptors in the serum of the patients with the cervical cancer]. / Wartosc oznaczania wybranych cytokin i ich rozpuszczalnych receptorów w surowicy chorych na raka szyjki macicy.

The study encompassed 146 women with recognized invasive cervical cancer in 4 clinical stages. Patients underwent therapy in Oncologic Gynaecology Department of Wroclaw Medical University in 2001 and 2002 years. The correlation between pretreatment serum level of proangiogenic and inflammation factors--VEGF, sTNF-R1, IL-6 and clinical stage or early effects of therapy were observed. The strong and statistically significant relationship between pretreatment serum level of IL-6 and sTNF-R1 and clinical stage with early effect of treatment were found. The statistically significant correlation between serum level of all investigated parameters and clinical stage of cervix cancer was noticed. VEGF wasn't an independent prognostic factor in the study, but the prognostic value of IL-6 was demonstrated.

[The results of breast conserving treatment in breast cancer]. / Wyniki leczenia oszczedzajacego chorych na raka sutka.

UNLABELLED: The aim of the work was to assess the results of breast conserving treatment (BCT) in early breast cancer in patients treated in Lower Silesian Oncology Centre. MATERIAL AND METHODS: Analysis of data from 167 women treated between 1997 and June 2003 with BCT and adjuvant therapy was performed. RESULTS: Only in 14 patients (8.3%) failure of treatment was observed. In 7 cases (4.8%) there was local recurrence, all of them underwent mastectomy m. Patey and they are all alive without disease symptoms. In 6 women (3.6%) dissemination of cancer was observed. Death of 5 patients (3%) between 21 and 68 months from operation took place. In Cox-Mantel test only dependency between N status and dissemination (p < 0.05) was noted. Better results of treatment were connected with estrogen receptor (ER) overexpression. Our results do not differ from data published by leading oncology centers around the world.

[Prognostic significance of microvessel density in ovarian cancer]. / Wartosc prognostyczna oznaczania gestosci unaczynienia guza w raku jajnika.

UNLABELLED: The antigen of endothelial cell which are the exponent of microvessels density in cancer tumor as CD31, CD34 and CD105 are the most common analysed markers of angiogenesis. The aim of the work was to analyse the expression of CD31, CD34 and CD105 antigens--three basic markers of microvessel density in ovarian cancer. MATERIAL AND METHODS: The material included 80 patients with ovarian carcinoma, treated between 1996 and 2001 in Department of Oncology Gynecology of Lower Silesian Centre of Oncology. The median of age was 54.4 years. Most of analyzed cases (n = 53) were serum ovarian carcinoma in III and IV FIGO stage. RESULTS: The correlations between microvessel density (MVD) and clinicopathological parameters were analyzed. We have stated that in patients younger than 50 years the microvessel density was lower. This correlation was statistically significant in the estimation of MVD by CD31 and CD34 expression and close to statistically significant by marked CD105 expression. In patients with time of menopause that occurred before 46 years of age, microvessel density marked with CD105 expression was significantly higher and close to significance in CD31 marker. CONCLUSIONS: Cox analysis proved that independent risk factors of death in patients with ovarian cancer were: age over 50 years, low degree of patient performance according to WHO (World Health Organization) scale, high FIGO (International Federation of Gynecology and Obstetrics) stage and high expression of CD34 microvessel density.

Tolerance of combined radiochemotherapy in cervical cancer patients.

BACKGROUND: Radiochemotherapy in cervical cancer was implemented to clinical practice based on 5 randomized clinical trials, published at the end of the 20th century, which showed improvement in the total and symptomless survivals by about 10-18%. The increase of therapeutic index of such treatment can take place only when the efficiency of the treatment outweighs the increase of its toxicity. Thus, it is necessary to monitor treatment reaction during radiochemotherapy. OBJECTIVES: The aim of this study was to assess the acute post-radiation reaction during radiochemotherapy for cervical cancer and the to analyze the reasons of the unplanned course of combined treatment. MATERIAL AND METHODS: A group of consecutive 176 cervical cancer patients in the clinical stage from IB to IIIB acc. to FIGO classification who underwent radiochemotherapy were taken under prospective observation in Clinical Gynecologic Radiotherapy Ward of the Lower Silesian Cancer Center in Wroclaw between April 2010 and September 2012. Early post-radiation reaction was assessed in RTOG/EORTC scale once a week. RESULTS: During the treatment early post-radiation reaction of upper part of alimentary duct was observed in 74.4% of the patients, the reaction of lower part of gastrointestinal tract in 51.2%, and in bladder 44.8%. The most frequent symptoms of post-radiation reaction are: nausea (73.3% of the patients), diarrhea (51.2%) and vomiting (20.9%). Leucopenia was observed in 97.1% of the patients, granulocytopenia in 70.4%, anemia in 69.2%, and thrombocytopenia in 25.5%. The planned dose of radiotherapy was administered completely in 90.1% of the patients. A break in radiotherapy was necessary in 15.7% of the patients. In total, 44.8% of the patients did not receive radiochemotherapy according to the plan, because of the side effects of the treatment (most often leucopenia, thrombocytopenia and gastrointestinal reaction). CONCLUSIONS: The presented data shows that radiochemotherapy causes the intensification of acute side effects of treatment and may cause unplanned course of treatment and prolongation of the total treatment time.

Prognostic significance of intracellular laminin and Her2/neu overexpression in non-small cell lung cancer.

UNLABELLED: This study was designed to test the hypothesis that Her2/neu expression, the level of intracellular laminin and Ki-67 index are of prognostic importance in patients with non-small cell lung cancer (NSCLC). The second aim of the study was to analyse the efficiency of post-operative radiotherapy in the group of patients treated at our hospital. MATERIALS AND METHODS: Tumor tissue samples were obtained from 64 patients with primary NSCLC, who were operated on and post-operatively irradiated. Immunohistochemical analyses were performed on paraffin blocks of resected lung tissue. Survival of the patients was calculated on the basis of 5-year follow up. RESULTS: From among the analysed factors only the enhanced expression of intracellular laminin, histological grade 3, adenocarcinoma type of cancer and statistically important radiotherapy parameters influenced patient survival. The influence of Her2/neu expression on survival almost reached statistical significance. In multivariate Cox analyses only the level of the intracellular laminin, overexpression of Her2/neu and dose time ratio (DTR) were found to be the independent risk factors for patients survival. CONCLUSION: Enhanced expression of intracellular laminin, Her2/neu overexpression and interruptions during post-operative radiotherapy are detrimental for survival in patients with NSCLC.

Mcm-2 protein expression predicts prognosis better than Ki-67 antigen in oral cavity squamocellular carcinoma.

BACKGROUND: The present study aimed at evaluating the expression intensities of the Mcm-2 protein and Ki-67 antigen in squamocellular carcinomas of the oral cavity and comparing their prognostic value. MATERIALS AND METHODS: Forty-nine patients, operated on and treated with radiotherapy for carcinoma of the oral cavity floor and/or the mobile part of the tongue, were retrospectively analyzed. RESULTS: A significant positive correlation was noted between the expression of Mcm-2 protein and that of the Ki-67 antigen, as well as an absence of such correlations with the remaining examined factors. A significant correlation with worse disease-specific survival period (DSS) in the group of patients demonstrating Mcm-2 protein expression in over 10% of cancer cells was detected (5-year cumulative DSS 50% vs. 76%). CONCLUSION: The results suggested that the expression of Mcm-2 protein may be used as a prognostic factor in patients with squamocellular carcinoma of the oral cavity.

CD24 expression is specific for tamoxifen-resistant ductal breast cancer cases.

BACKGROUND: In breast cancer, the expression of CD24 represents a poorly recognised unfavourable prognostic factor. CD24 has been described to be potentially down-regulated by estrogen receptor alpha (ER). The present study was aimed at examining the predictive value of CD24 expression in tamoxifen-treated breast cancer cases. MATERIALS AND METHODS: Sixty patients with primary invasive ductal breast cancers with post-operative tamoxifen treatment were enrolled in the study. Immmunohistochemical reactions were performed using monoclonal antibodies directed against CD24 and ER. RESULTS: Cases demonstrating cytoplasmic-membranous expression of CD24 (CD24c-m) proved to be characterised by a significantly lower expression of ER as compared to CD24c-m-negative cases. A multivariate progression analysis based on the Cox proportional hazard model demonstrated that CD24c-m expression is an independent prognostic factor for poor overall survival. CONCLUSION: The data from the present study suggested that CD24c-m expression is specific for tamoxifen-resistant breast cancer cases. CD24 should be subjected to comprehensive studies as a marker of resistance to tamoxifen treatment.