Tumor Mitotic Rate Research Articles

Update on management of GIST and postsurgical use of imatinib

Update on management of GIST and postsurgical use of imatinib E Pennacchioli, C Colombo, M Berselli, A GronchiSurgical Department, Melanoma and Sarcoma Unit, IRCCS Istituto dei Tumori, Milan, ItalyAbstract: The advent of imatinib is a milestone in the treatment for locally advanced and ­metastatic gastrointestinal stromal tumor (GIST) at a dose of 400 mg/day. A higher starting dose of 800 mg/day is recommended only for patients harboring the KIT exon 9 mutation. Studies of imatinib plasma levels are presently ongoing, possibly leading to dose adjustments in the single patient. In localized GIST, complete surgical excision (R0) is considered the standard treatment. Imatinib pretreatment is recommended if R0 surgery is not feasible, or if less mutilating surgery might be achieved by cytoreduction. Whenever surgical morbidity is expected to be an issue, imatinib should be considered even for resectable primary disease in the preoperative setting. Patients with completely resected primary GIST at significant risk of recurrence (based on tumor mitotic rate, size, and location) can be considered for adjuvant imatinib. Dose adjustments could be considered for exon 9 mutant GIST. Imatinib is well tolerated, and its side effects including nonhematologic (periorbital edema, fatigue, nausea, diarrhea, myalgia, skin rash, headache, and abdominal and chest pain) and hematologic (anemia, granulocytopenia, and particularly neutropenia) toxicities are usually mild, although the severity of adverse events increases with dose. While treatment should be continued indefinitely in advanced/metastatic patients, because its interruption is generally followed by relatively rapid tumor progression, the optimal duration of postoperative imatinib therapy is presently not known, even if it is likely that longer disease control will be obtained with longer treatment duration. Patients should be aware that it is not possible thus far to predict the impact of adjuvant therapy on survival. However, the impact on disease control has been dramatic, and imatinib represents a major step forward in the treatment of this rare disease.Keywords: GIST, imatinib mesylate, adjuvant therapy

Relation of tumor pathologic and molecular features to outcome after surgical resection of localized primary gastrointestinal stromal tumor (GIST): Results of the intergroup phase III trial ACOSOG Z9001.

10006 Background: Adjuvant therapy with imatinib mesylate increases recurrence-free survival (RFS) in primary GIST (Lancet 2009). However, the effect of tumor pathologic and molecular factors on outcome in patients treated with or without adjuvant imatinib is uncertain. Methods: 713 patients with a KIT-expressing, ≥3 cm, primary GIST were randomized postoperatively in a double-blind manner to 1 year of 400 mg imatinib or placebo daily. Patients underwent serial (q3 months x8 then q6 months x6) cross-sectional imaging. Mitotic rate (mitoses per 50 high power fields) and KIT and PDGFRA mutation status were determined by central pathologic analyses. Tumor mitotic rate, size, location, and mutation status were available in 513 patients. Results: Tumor size was <5 cm in 41% of patients, 5-10 cm in 34%, and ≥10 cm in 25%. Tumor location was stomach (65%), small bowel (31%), rectum (1%), or other (3%). Mitotic rate was high (≥5) in 39% of patients. The most common (68%) mutation occurred in KIT exon 11. At a median follow-up of 20 months, 2 year RFS was 74% in the placebo arm vs. 91% in the imatinib arm. On multivariate analysis of the placebo arm, RFS was worse with high mitotic rate (p<0.0001, HR 17.1), tumor size (p<0.01, HR 1.7), small bowel location (p<0.05, HR 2.1), and KIT exon 11 mutation (p<0.05, HR 3.0). On multivariate analysis of the imatinib arm, RFS was worse with high mitotic rate (p<0.001, HR 7.4), tumor size (p<0.01, HR 2.9), and small bowel (p<0.05, HR 3.1) or rectal (p<0.05, HR 5.4) location. In the placebo and imatinib arms respectively, 2 yr RFS was 65 vs. 91% (p<0.0001) for KIT exon 11 mutation and 76 vs. 100% (p<0.01) for PDGFRA mutation. Notably, there was only 1 event in the 28 total patients with a PDGFRA D842V mutation. Patients with a KIT exon 9 mutation assigned to placebo (n=13) had a 1 yr RFS of 80% vs. 100% on the imatinib arm (n=22), but overall RFS was not different. There was no statistical difference in RFS between arms in the 64 patients with wild-type KIT and PDGFRA. Conclusions: Tumor pathologic features and mutation status are both prognostic and predictive for RFS after surgical resection of primary GIST. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Novartis, Pfizer Novartis, Pfizer Novartis, Pfizer Pfizer

The Prognostic Value of Tumor Mitotic Rate and Other Clinicopathologic Factors in Patients with Locoregional Recurrences of Melanoma

Tumor mitotic rate (MRP) is an independent prognostic factor in clinically localized primary cutaneous melanoma, but the prognostic importance of mitotic rate in melanoma recurrences (MRR) is not known. In this study, we sought to determine the prognostic value of MRR and other clinicopathologic factors in recurrent melanoma. Patients with primary cutaneous melanoma diagnosed between 1979 and 2006, who subsequently developed recurrence(s), were studied. Histologic sections of primary and first locoregional recurrences of melanoma were examined, and MRP and MRR were measured. Relationships between MRR, known prognostic parameters in melanoma, time to first recurrence (TTR), and postrecurrence survival were analyzed. A total of 279 patients (172 men, 107 women) had AJCC stage I (n=97) or stage II (n=182) melanoma. Median MRP and MRR were 4/mm(2) (0-34) and 4/mm(2) (0-51), respectively. There was weak association between MRP and MRR (R (2)=0.02, p=0.02). Independent predictors of poorer postrecurrence survival were shorter TTR (hazard ratio, 0.74; 95% confidence interval, 0.61-0.90, p=0.003) and recurrence type (10-year postrecurrence survival for local, lymph node, and in-transit recurrences: 70%, 21.5%, and 11.1%, respectively; p=0.04). MRR >0 was associated with poorer 10-year postrecurrence survival (39.1%) than if MRR=0 (51.2%), but the difference did not reach statistical significance (p=0.15). However, the difference in survival between patients with MRR >0 and those with MRR=0 increased with time. TTR is an independent predictor of postrecurrence survival. Because survival in patients with MRR >0 decreases with time (relative to those with MRR=0), MRR should be routinely measured so that future studies can determine whether MRR has any independent predictive value.

Abstract 3312: Molecular profiling of melanoma primary tumors

Abstract Objectives: A number of pathologic features have been identified from primary melanoma that are useful for determining patient prognosis including tumor thickness, ulceration, mitotic rate and Clark level; and the tumor status of the sentinel nodes (SN). Because none of these factors is useful for evaluating the outcome of individual patients we used a cDNA microarray to determine the relevance of molecular profiling of the primaries to determine the presence of lymph node metastases. Methods: We obtained intact melanoma primaries and SN from 12 patients and microdissected both for molecular analysis. RNA was extracted and purified by RNeasy (Qiagen, Valencia, CA). GEArray Q series-Human Tumor Metastasis Gene Array Kits (Superarray, Bethesda, MD) were used to evaluate gene expression from biotinylated cDNA and images were acquired on the Molecular Dynamics storm 860 imaging station (Amersham Pharmacia Biotech, United Kingdom, Ltd). The signal intensity which corresponds to the quantity of cDNA bound to the array was analyzed by the ScanAlyze V2.50 image analysis software (Covance, Berkeley, CA). Results: RNA was evaluated from 12 primary melanoma and matching SN, 7 with metastases. Four genes: caveolin (CAV1), Lim kinase (LIMK), matrix metalloproteinase 15 (MMP15) and vascular endothelial growth factor (VEGF) demonstrated consistent up-regulation in primary melanoma associated with SN metastases identified by H &amp; E and the presence of these genes expressed in SN. Human melanoma cell lines and tumor-negative SN served as controls. Receiver operator curves (ROC) for genes: CAV1, LIMK, MMP15 and VEGF were constructed and the area under the curves (AUC) were determined as: 0.956+0.056, 0.978+0.039, 0.822+0.114 and 0.91+0.08, respectively. The combined concordance of LIMK and VEGF to predict metastases was 0.94 Conclusions: Gene expression profiling of primary melanoma can be used for predicting the presence of SN metastases. Up-regulation of LIMK and VEGF from the primary tumors may be an important first step to understand the early mechanism for patients developing lymph node metastases. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3312.

Lactate dehydrogenase 5 expression in melanoma increases with disease progression and is associated with expression of Bcl-XL and Mcl-1, but not Bcl-2 proteins

The serum level of lactate dehydrogenase (LDH) is an important predictor of prognosis and treatment response in melanoma patients. It is unknown whether the expression of LDH-5 in tissue sections also has prognostic significance and whether it is related to the expression of the anti-apoptotic proteins, Bcl-2, Bcl-XL and Mcl-1, and endoplasmic reticulum stress protein glucose-regulated protein 78 (GRP78). Identification of an association between LDH-5 expression and anti-apoptotic proteins may have important therapeutic implications for melanoma patients. Sections from 159 pigmented lesions, including nevi and melanoma at different stages of progression were studied by immunohistochemistry. Correlation of LDH-5 expression with clinicopathological factors and with the expression of Bcl-2, Bcl-XL, Mcl-1 and GRP78 was examined. LDH-5 was detected at low levels in 6 of 10 compound nevi (60%) and 6 of 10 dysplastic nevi (60%). The percentage of positive cases was greater in thin (≤1.0 mm) (74%) and thick primary melanoma (>1.0 mm) (95%) and in metastatic melanoma in the skin (100%) and lymph node (81%). The immunoreactive score was highly related to progression of melanoma (P<0.0001). LDH-5 expression was positively associated with increasing tumor thickness (P=0.02) and dermal tumor mitotic rate (P=0.02). LDH-5 above the median immunoreactive score was associated with reduced disease-free survival and overall survival (P<0.02). LDH-5 expression was negatively associated with Bcl-2 expression. In contrast, LDH-5 expression was strongly associated with Bcl-XL and Mcl-1 expression and also positively associated with GRP78 expression (P<0.0001). The low Bcl-2 expression in melanomas with high LDH-5 expression provides an explanation for the poor response of patients with high serum LDH levels to treatment with the Bcl-2 antisense drug ‘Genasense’. The strong correlation of LDH-5 expression with Mcl-1 expression suggests that treatment strategies inhibiting the activity of Mcl-1 in melanoma patients should be investigated.

Atypical Spitzoid Melanocytic Tumors With Positive Sentinel Lymph Nodes in Children and Teenagers, and Comparison With Histologically Unambiguous and Lethal Melanomas

Children and teenagers with a positive sentinel lymph node (SLN) after a prior diagnosis of an atypical spitzoid melanocytic tumor (ASMT) are usually cared for clinically in the same way as patients with melanoma. Little is known about long-term follow-up of these individuals to determine whether this practice is appropriate. To learn more about the biology of these tumors we retrospectively reviewed the clinical and pathologic findings of children and teenagers (<18 y of age at the time of diagnosis) with an ASMT, positive SLN and follow-up of at least 3 years. Their findings were compared with histologically unambiguous melanomas of children or teenagers, who had a positive SLN or died of metastatic melanoma. Eleven individuals, 6 girls and 5 boys, with primary ASMT and positive SLN were identified. The primary tumors ranged in thickness from 2.1 to 12 mm (median, 4.6 mm; mean, 5 mm). The tumor mitotic rate ranged from 1 to 10 mitoses/mm (median, 3/mm, median, 3/mm). The positive SLNs included 6 nodes with intranodal melanocytic aggregates measuring <1 mm in greatest dimension, and 5 nodes, in which the size of the melanocyte deposits was >/=1 mm. All the patients with ASMT and positive SLN remained free of disease with a median follow-up of 47 months (mean, 61 mo, range: 36 to 132 mo). In contrast, 2 of 5 patients <18 years of age with a histologically unambiguous melanoma and a positive SLN died of metastatic melanoma. The overall disease-specific mortality rate for all patients <18 years of age diagnosed with melanoma was 12%. Our findings confirm that children and teenagers with ASMTs and positive SLNs have a less aggressive clinical course than those with histologically unambiguous melanoma.

Role of Sentinel Lymph Node Biopsy in Patients with Thin Melanoma

Sentinel lymph node (SLN) biopsy has emerged over the past 2 decades as a rational approach for staging regional lymph nodes in patients with clinically node-negative melanoma (stage I and II disease). Large multi-institutional studies have confirmed that when performed by experienced surgeons, it is an accurate, reliable technique for identifying occult regional nodal disease, and that SLN status is the most important prognostic factor in patients with stage I and II melanoma. However, the incidence of occult regional nodal metastasis in patients with thin melanoma (<or= 1.0 mm; approximately 70% of patients with newly diagnosed melanoma) is low, and whether to perform SLN biopsy in these patients remains controversial. Several predictors of SLN metastasis in patients with thin melanoma have been suggested, but none widely accepted. This article reviews current literature on these predictors in patients with thin melanoma. Although the ability to draw conclusions was limited by the size and design of the available studies, the authors tentatively conclude that SLN biopsy can be considered for patients with melanomas 0.75 mm or larger, those with T1b melanomas (i.e., <or= 1.0 mm; Clark level IV/V and/or ulcerated), and those with thin melanomas with an increased tumor mitotic rate (especially >or= 1 mitosis/mm2). Including younger age (e.g., <or= 40 years) in the decision also seems reasonable, particularly if the primary tumor is associated with a high tumor mitotic rate. Tumor regression does not seem to be associated with an increased risk for SLN metastasis. Firm conclusions on the predictive value of vertical growth phase, absence of tumor-infiltrating lymphocytes, or male gender were not possible, particularly if used as a sole criterion for offering this procedure. SLN biopsy should be discussed with all patients with newly diagnosed thin melanoma.

Follow-up schedules after treatment for malignant melanoma

Existing follow-up guidelines after treatment for melanoma are based largely on dated literature and historical precedent. This study aimed to calculate recurrence rates and establish prognostic factors for recurrence to help redesign a follow-up schedule. Data were retrieved from the Sydney Melanoma Unit database for all patients with a single primary melanoma and American Joint Committee on Cancer (AJCC) stage I-II disease, who had received their first treatment between 1959 and 2002. Recurrence rates, timing and survival were recorded by substage, and predictive factors were analysed. Recurrence occurred in 18.9 per cent (895 of 4748) of patients overall, 5.2 per cent (95 of 1822) of those with stage IA disease, 18.4 per cent (264 of 1436) with IB, 28.7 per cent (215 of 750) with IIA, 40.6 per cent (213 of 524) with IIB and 44.3 per cent (86 of 194) with IIC disease. Overall, the median disease-free survival time was 2.6 years, but there were marked differences between AJCC subgroups. Primary tumour thickness, ulceration and tumour mitotic rate were important predictors of recurrence. A new follow-up schedule was proposed: stage I annually, stage IIA 6-monthly for 2 years and then annually, stage IIB-IIC 4-monthly for 2 years, 6-monthly in the third year and annually thereafter.

Surgical Outcomes of Patients with Gastrointestinal Stromal Tumors in the Era of Targeted Drug Therapy

BackgroundThe discovery of the c-KIT mutation and the advent of targeted drug therapy with imatinib mesylate have revolutionized the management of gastrointestinal stromal tumors (GISTs). The outcome of patients with surgically treated GISTs treated in the era of targeted drug therapy was assessed and factors associated with adverse outcomes determined. Materials and MethodsPatients with GISTs requiring surgery at a tertiary care center from 2002 to 2007 were reviewed and prognostic factors determined. ResultsForty patients were surgically treated for GISTs. The median age at presentation was 59 years. The stomach (55%) was the main site of primary disease. The median tumor size was 7 cm. Eleven (28%) patients had metastatic disease at presentation. Surgery was undertaken in all patients with curative intent. Multi-organ resection was required in 10 (25%) patients. Imatinib mesylate was administered postoperatively in 68% of cases. Median follow-up was 24 months. There was a 40% recurrence rate with 63% undergoing repeat surgical resection. The peritoneum and liver were the main sites of recurrent disease. The 5-year disease-specific survival and disease-free survival (DFS) were 65% and 35%, respectively. High mitotic rate (P = 0.017) and tumor size greater than 10 cm (P = 0.009) were the only prognostically significant adverse factors of DFS on multivariate analysis, independent of imatinib mesylate treatment. ConclusionAggressive surgical treatment and follow-up of GISTs, combined with targeted drug therapy, leads to long-term DFS survival. Tumor recurrence is independently associated with a high tumor mitotic rate and size greater than 10 cm, despite the use of adjuvant targeted drug therapy.

Phospho-ERK (pERK) and Ki67 expression as compared to thickness and mitotic rate (MR) as prognostic factors in patients with stage I/II melanomas

9020 Background: Tumor thickness and MR in the vertical growth phase (VGP) are key prognostic factors for melanoma patients. We hypothesized that the expression of two biomarkers associated with proliferation, Ki67, a measure of cell division, and pERK, a consequence of melanoma cells signaling through the MAP kinase pathway, would be associated with poor prognosis and more accurately predict those who would have a metastasis within ten years (MET). Methods: We evaluated Ki67 and pERK expression by immunohistochemistry in a nested cohort study of 50 patients with stage I/II VGP melanomas seen at Penn's Pigmented Lesion Clinic (1972–91). Ki67 expression was determined by the % of melanoma cells positive in VGP hot spots. Nuclear pERK expression by melanoma cells in the tumor's invasive edge (pERK/IE) was quantified using a modified H-score. Cut-points for both were established by maximizing the difference between survival distributions. Fisher's exact test (0.05, one-sided) had 75% power to detect an odds ratio (OR) of 4.3 with 19 and 42 patients with and without MET. Results: The odds of MET were 10.6-fold and 4.3-fold higher in patients having high Ki67 (p=0.013) and high pERK/IE (p<0.01) expression, respectively, compared to those with low expression. Thickness (OR=1.7, p=0.004) and MR (OR=1.3, p=0.002) were also each associated with MET. In the multivariate model the adjusted odds ratios for Ki67 and pERK/IE remained strong [4.0 (p=0.061) and 5.9 (p=0.030)], but thickness and MR were no longer significant. Conclusions: New biomarkers strongly associated with clinical outcome are needed. Both Ki67 and pERK/IE expression were strongly associated with prognosis, were notably more informative than thickness and MR in predicting MET, and are therefore candidates for validation in larger datasets. No significant financial relationships to disclose.

Predicting Outcomes in Metastatic Melanoma

Predicting Outcomes in Metastatic Melanoma

Tumor mitotic rate, size, and location independently predict recurrence after resection of primary gastrointestinal stromal tumor (GIST)

Gastrointestinal stromal tumor (GIST) is the most frequent sarcoma of the intestinal tract and often shows constitutive activation of either the KIT or PDGFRA receptor tyrosine kinases because of gain-of-function mutation. Although the efficacy of tyrosine kinase inhibitors in metastatic GIST depends on tumor mutation status, there have been conflicting reports on the prognostic importance of KIT mutation in primary GIST. A total of 127 patients were studied who presented to our institution from 1983 to 2002 with localized primary GIST and underwent complete gross surgical resection of disease. The majority of tumors originated in the stomach (58%) or small intestine (28%). By using polymerase chain reaction (PCR) and direct sequencing, a KIT mutation was found in 71% of patients and a PDGFRA mutation in 6%. After a median follow-up of 4.7 years, recurrence-free survival was 83%, 75%, and 63% at 1, 2, and 5 years, respectively. On multivariate analysis recurrence was predicted by > or =5 mitoses/50 high-power fields, tumor size > or =10 cm, and tumor location (with patients having small bowel GIST doing the worst). In particular, a high mitotic rate conferred a hazard rate of 14.6 (95% confidence interval, 6.5-32.4). Specific KIT mutations had prognostic importance by univariate but not multivariate analysis. Patients with KIT exon 11 point mutations and insertions had a favorable prognosis. Those with KIT exon 9 mutations or KIT exon 11 deletions involving amino acid W557 and/or K558 had a higher rate of recurrence, whereas patients without a tyrosine kinase mutation had intermediate outcome. In the absence of therapy with tyrosine kinase inhibitors, recurrence in completely resected primary GIST is independently predicted by mitotic rate, tumor size, and tumor location.

Incidence of gastrointestinal stromal tumors (GISTs) in France: Results of the PROGIST survey conducted among pathologists

10047 Background: GISTs are the most common mesenchymal tumors of the gastrointestinal tract but data on the annual incidence of this tumor is scarce due to previous lack of well-defined pathologic criteria. The aim of this study was to investigate the incidence of GISTs in France and describe the distribution according to age, sex, circumstances of discovery, localization and risk categories. Methods: This prospective epidemiologic study was performed among pathologists who were asked to declare all the cases of GIST over a one year period. All pathology centers (330 centers) in France were proposed to participate and asked to report exhaustively the cases diagnosed from 1 December 2004 to 30 November 2005. Results: 591 cases of GISTs were reported, 535 new cases and 56 cases of relapse. However, some large centers were not able to participate. So, the annual estimated incidence was 12 cases/million inhabitants in France. The main characteristics of the new cases of GIST were as follows: mean age 65 (± 13.2) (range: 16–93) years, 48.6% men and 51.4% women, circumstances of discovery: fortuitous 163 (30.5%), symptomatic 249 (46.5%), unknown 123 (23%). The primary tumor locations were: stomach 341 (63.7 %), small intestine 115 (21.5%), mesentery 35 (6.5%), colon/rectum 17 (3.2%), esophagus 4 (0.7%), unknown 23 (4.3%). 95.3% of GISTs were cKIT (CD117) + and 3.7 % were cKIT -. According to the Fletcher consensus criteria, based on tumor size and mitotic rate, among the 490 localized GISTs 14.7% were considered to be at very low prognostic risk, 25.5% at low-risk, 23.1 % at intermediate risk and 23.1 % at high-risk. For 13.6 % data were missing. Conclusions: This study is providing for the first time an estimation of the annual incidence of GISTs and a description of the characteristics of these tumors in France based on pathology registration. The true incidence may be slightly higher as some large centers were not able to reported their cases. These results are comparable to what has been reported in recent studies in other European countries. No significant financial relationships to disclose.

Mcl-1, Bcl-XL and Stat3 expression are associated with progression of melanoma whereas Bcl-2, AP-2 and MITF levels decrease during progression of melanoma

AbstractMembers of the Bcl-2 family of antiapoptotic proteins (Bcl-2, Bcl-XL and Mcl-1) are key regulators of apoptosis. The purpose of the present study was to examine and better define the role of Bcl-2, Bcl-XL and Mcl-1 in the progression of melanoma. Immunohistochemical staining for Bcl-2, Bcl-XL and Mcl-1 was performed on paraffin sections of 100 cases of benign nevi, primary melanoma and metastatic melanoma. Expression was correlated with histopathologic features, clinical progress and expression of transcription factors (AP-2, MITF and p-Stat3). Bcl-2 was expressed in 100% of benign nevi and thin melanoma (≤1.0 mm) but was less in thick melanoma (>1.0 mm) (88%), subcutaneous (62%) and lymph node metastases (35%). In contrast, Bcl-XL and Mcl-1 were expressed at lower levels in nevi and thin melanoma compared to Bcl-2 but their expression was much higher in thick melanoma and in subcutaneous and lymph node metastases (P<0.0001). Bcl-2 expression was negatively associated with tumor thickness (P<0.05) but Bcl-XL expression increased with increasing tumor thickness (P<0.05) and dermal tumor mitotic rate (P<0.05). Similarly Mcl-1 expression increased with increasing tumor thickness (P<0.09) and dermal tumor mitotic rate (P<0.17). Bcl-2 expression was positively correlated with expression of the transcription factors microphthalmia transcription factor (MITF) and nuclear AP-2 whereas Bcl-XL (and Mcl-1) expression were positively correlated with p-Stat3. This study is the first to show a clear dissociation between changes in Bcl-2 expression (downregulation) and Bcl-XL, Mcl-1 expression (upregulation) during progression of melanoma. The results were also consistent with a role for AP-2 and MITF in regulation of Bcl-2 and pStat3 in regulation of Bcl-XL. These findings have important implications for the development of treatments targeting antiapoptotic proteins in patients with melanoma.

The impact of c-kit mutations on histomorphological risk assessment of gastrointestinal stromal tumors

BACKGROUND: Gastrointestinal stromal tumors (GISTs) are characterized by gain of function mutations of the protooncogene c-kit. We decided to investigate the impact of c-kit mutations on tumor size and mitotic rate, the two most important features for histomorphological risk assessment of GISTs summarized in the Fletcher scheme. METHODS: We examined 43 GIST cases for c-kit mutations in exons 9 and 11 by polymerase chain reaction (PCR) amplification and genomic sequencing. RESULTS: c-kit mutations were detected in 44.2% of the analysed GISTs. In statistical analysis we did not find an effect of c-kit mutations on tumor size and mitotic rate. Furthermore, we detected a slight positive correlation of MIB1 and tumor risk. CONCLUSIONS: We found c-kit mutations variably distributed among all tumor risk groups. Thus, our results showed that c-kit mutation analysis was not a helpful instrument in routine histomorphological risk assessment of GISTs based on the Fletcher classification.

BRCA1 promoter methylation in sporadic breast tumors: relationship to gene expression profiles

BRCA1 is a tumor suppressor gene that functions in DNA repair. Basal-like tumors are a distinctive subtype of breast cancer defined by gene expression profiles. Hereditary BRCA1 breast tumors and basal-like sporadic tumors have a similar phenotype and gene expression signature, suggesting involvement of BRCA1 in the pathogenesis of sporadic basal-like cancer. This study evaluates the role of BRCA1 in sporadic breast tumorigenesis. BRCA1 protein expression and promoter methylation are compared to tumor histopathology and gene expression profiles. We find BRCA1 protein expression correlates with tumor mitotic rate, consistent with normal cell-cycle regulation of the BRCA1 gene. Methylation is found in 21% of tumors and is associated with lower BRCA1 protein, but not with specific pathologic features. Basal-like tumors, defined by hierarchical clustering of gene expression, have infrequent BRCA1 methylation and high levels of BRCA1 protein expression consistent with their high mitotic rate. Tumors with BRCA1 promoter methylation are present in all expression clusters; however, a subgroup of ER-positive high-grade tumors has a significantly greater number of BRCA1 methylated tumors. Absence of BRCA1 promoter methylation and high levels of BRCA1 expression in basal-like sporadic tumors suggest alternate explanations for the phenotypic similarities of these tumors to hereditary BRCA1 tumors.

Granulosa Cell Tumours of Ovary: Variables Affecting Prognosis

Background: Granulosa cell tumours account for less than 5 percent of all ovarian malignancies. Limited data is available from India. Methods: 27 patients with diagnosis of granulosa cell tumour of the ovary were treated between 1991 and 2003 at our Institute. The surgical records were reviewed and the patients were staged according to the FI6O system. The clinical and histological findings are correlated with prognosis and survival. Results: Mean age at diagnosis was 46.2 (2-64) years. The numberof patients in various stages was 1-19; II-l; III-5 and IV-2. Menstrual irregularity was diagnosed in 22 percent, and postmenopausal bleeding in 7.4 percent of women. Twenty-five patients were treated with primary surgery, 9 patients received adjuvant chemotherapy (CT) and only one patient received chemotherapy as primary treatment. Overall survival was 82 percent at 5 years. Overall survival for stage I was 100 percent after 5 and 10 years and in stage II-IV, was 56.4 percent after 5 and 10 years. Meantumour size was 18cm (range 3-30 cm). Women with larger tumour diameter (greater than 15cm) had significantly worse outcome than those with tumours of smaller diameter (P less than 0.05). The frequency of observed mitosis influenced the survival rate; with 0-3/10, HPF the survival was 100 percent in 5 years and with 4/10, HPF the survival was 2.6 years. Conclusion: The tumour size, mitotic rate and stage of disease are well-defined variables and influence the survival significantly and should be considered as important prognostic factors for treatment planning.

Cutaneous desmoplastic melanoma: reappraisal of morphologic heterogeneity and prognostic factors.

Desmoplastic melanoma (DM) is a variant of melanoma, which may be confused with nonmelanocytic benign or malignant spindle cell proliferations. The histologic hallmark of DM is the presence of fusiform melanocytes dispersed in a prominent collagenous stroma. Phenotypic heterogeneity of DM is underrecognized. Desmoplasia may be prominent throughout the entire tumor ("pure" DM) or represent a portion of an otherwise nondesmoplastic melanoma ("combined" DM). We reviewed melanomas with desmoplasia from 92 patients seen at a single institution between 1980 and 2002. Fifty-five of the tumors were pure DM. Thirty-seven were classified as combined. Mean follow-up of patients was 46 months for those alive at the last follow-up. Univariate analysis of clinical and pathologic parameters revealed four significant variables for disease-free survival: Clark level (IV vs. V; P = 0.005), DM subtype (pure vs. combined; P = 0.01), tumor mitotic rate (<1, 1-4, >4 mitoses/mm; P = 0.01), and tumor thickness (<1 mm, 1-4 mm, >4 mm; P = 0.02). Only histologic subtype (P = 0.02) and Clark level (P = 0.05) were independently significant by Cox regression analysis. Our results indicate that distinguishing pure from combined forms of DM is clinically relevant for prognosis (pure forms being associated with longer disease-specific survival). Failure to make this distinction may account for conflicting reports in the literature on the biologic behavior and prognosis of DM.

The prognostic importance of tumor mitotic rate confirmed in 1317 patients with primary cutaneous melanoma and long follow-up.

The late Dr. Vincent McGovern (1915 to 1983) was an international authority on melanoma pathology and one of the first to suggest that assessment of tumor mitotic rate (TMR) might provide useful prognostic information. Data for a large cohort of patients, now with extended follow-up, whose tumors had been assessed by Dr. McGovern were analyzed to reassess the independent prognostic value of TMR in primary localized, cutaneous melanoma. Information was extracted from the Sydney Melanoma Unit database for 1317 patients treated between 1957 and 1982 for whom there was complete clinical information and whose primary lesion pathology, which included tumor thickness, ulcerative state, and TMR, had been assessed by Dr. McGovern. All these assessments were made according to the recommendations of the Eighth International Pigment Cell Conference, held in Sydney in 1972 under the auspices of the International Union Against Cancer. Factors predicting melanoma-specific survival were analyzed with the Cox proportional hazards regression model. Stage, according to the recently revised American Joint Committee on Cancer Staging System (which is based on tumor thickness and ulceration) was the most predictive factor for survival (P<.0001). This was followed by primary lesion site (P<.0001), patient age (P=.0005), and TMR (P=.008). TMR was confirmed to be an important independent predictor of survival of patients with primary cutaneous melanoma. However, its predictive value was less than it was when assessed according to the 1982 revisions of the 1972 TMR recommendations.

Endometrial Stromal Sarcoma

Uterine sarcomas comprise 2–3% of all uterine malignancies. Tumors in this category are, in order of decreasing incidence, carcinosarcoma, leiomyosarcoma, endometrial stromal sarcoma, and adenosarcoma. Endometrial stromal sarcomas are divided into low- and high-grade according to tumor cell morphology and mitotic rate. Low-grade tumors are characterized by a slow growth pattern, presence of estrogen and/or progesterone receptors, and an indolent clinical course with late recurrences. Despite this indolent course, 37–60% of patients with early-stage disease experience recurrent disease. High-grade stromal sarcomas, on the other hand, exhibit more aggressive biological behavior and poor outcome. The standard treatment for localized endometrial stromal sarcomas is total abdominal hysterectomy and bilateral salpingo-oophorectomy. Adjuvant radiation therapy appears to reduce locoregional failure, although its benefit in terms of overall survival is unknown. Progestogens have been considered first-line therapy in recurrent low-grade tumors, with durable response rates of approximately 50%. Some authors also favor their use in the adjuvant setting, although no clear data exist to support this indication as a standard approach. Other hormonal approaches such as aromatase inhibitors may provide an alternative to progestogens in light of a more favorable toxicity profile and similar antitumor activity. Chemotherapy, including anthracyclines, is generally reserved for recurrent low-grade tumors that progress on hormonal therapies and for high-grade lesions that usually lack hormone receptors. The combination of chemotherapy and hormones may be considered in highly symptomatic patients or in those with high-volume, life-threatening disease. In summary, endometrial stromal sarcoma of the uterus is a rare disease that should be treated with radical surgery. Prognostic factors according to tumor stage, mitotic count, and tumor grade can, to some extent, predict biologic tumor behavior and prognosis. The role of postoperative radiation therapy and adjuvant progestogens, particularly for low-grade disease, remains to be defined. Recurrent or metastatic disease should be treated with systemic therapy, and the choice between hormonal therapy and chemotherapy should be based on histologic characteristics including mitotic count, cell morphology, and estrogen and progesterone receptor status. Salvage surgery and/or radiation have been associated with some long-term remissions, and can be considered as part of the multimodality approach in selected cases. New prognostic markers and specific therapeutic targets are clearly needed in this rare disease.