The association of genitourinary cancer among Saudi patients with gastrointestinal stromal tumors and a systematic literature review

The gastrointestinal tract's most commonly occurring primary mesenchymal tumor is the gastrointestinal stromal tumor (GIST). However, few cases worldwide were reported associated with renal cell carcinoma (RCC). Therefore, we aimed to identify the association of genitourinary tumors in patients with GIST in our tertiary care hospital in Saudi Arabia and compare it to the literature. We identified all patients in the pathology department database with the diagnosis of GIST. We excluded duplicate and recurrent cases. We examined patients' files for the presence of RCC, adrenal tumors, or other genitourinary cancer. A systematic review of the association was conducted. From 2003 to 2020, 170 patients had a histopathologic diagnosis of primary GIST, 100 men and 70 women, median age of 57 (range 9-91) years at the time of diagnosis. The site of primary GIST was gastric 103, small bowel 43, mesenteric 5, omentum/peritoneum 7, abdomen 4, isolated adrenal 1, and other 7. Six patients had associated primary genitourinary cancer. Three patients had RCC (two clear cell RCC and one radiologic diagnosis only), and three had adrenal tumors (one adrenal carcinoma, one an isolated adrenal GIST, and one pheochromocytoma). In addition, two patients had a tumor invading the urinary bladder. Although the cohort included 63 men aged 60 or above (median 71 ± 8.7 years, range 60-94), none demonstrated clinical prostatic carcinoma. Data was compared to 69 systematic review articles. We report the rare association between GIST tumors and primary genitourinary cancer, mainly RCC and adrenal tumors. Also, we identified a secondary invasion of the urinary bladder. Unlike the reported series, none of the older male patients had clinical prostate cancer.

Radiochemotherapy with temozolomide for patients with glioblastoma. Prognostic factors and long-term outcome of unselected patients from a single institution

BACKGROUND

The objective of this retrospective analysis was to assess long-term outcome and prognostic factors of unselected patients treated for glioblastoma (GB) at a single center with surgery, standard radiotherapy (RT), and concomitant temozolomide (TMZ). From 1999-2005, the institutional protocol included surgery and RT with TMZ. From 2005 on, adjuvant TMZ was routinely added.

PATIENTS AND METHODS

Between April 1999 and September 2009, 181 patients with GB were treated with RT (60 Gy in 30 fractions) and concomitant TMZ (75 mg/m2/day throughout RT). Biopsy only had been performed in 53 patients (29.3%), 128 patients (70.7%) had undergone resection, which was complete based on postoperative MRI in 51 patients (28.2%). Adjuvant TMZ was applied in 67 of 181 patients (37%).

RESULTS

Median overall survival (OS) and progression-free survival (PFS) were 15.0 (95% CI, 13.1-16.8) and 7.2 months (95% CI, 5.9-8.5), respectively. After complete resection, partial/subtotal resection and biopsy, median OS was 23.20, 14.75, and 7.89 months (p<0.001), respectively. In multivariate Cox proportional hazards regression models, extent of resection (p<0.0001), Karnofsky's performance score (p<0.0001) and adjuvant TMZ (p=0.001) were significant independent prognostic factors for OS. RT with concomitant TMZ was well tolerated in the majority of patients and could be completed as scheduled in 146 patients (80.7%), while 11 patients (6.1%) discontinued RT. Another 35 patients (19.3%) interrupted concomitant chemotherapy.

CONCLUSION

RT with concomitant TMZ is a feasible regimen with acceptable toxicity in routine practice. Our data are compatible with a beneficial effect of adjuvant TMZ on OS and PFS.

Diagnosis of gastrointestinal stromal tumor (GIST) on transurethral resection of the prostate: a case report and review of the literature

Gastrointesinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract and they show differentiation towards interstitial cells of Cajal (ICC). Herein, we describe a case of a 60-year-old man presenting with symptoms mimicking adenomatous hyperplasia of the prostate that was subjected to repeated transurethral prostatectomies. Histologic and immunohistochemical examination showed a neoplastic process with characteristics consistent with GIST. Imaging studies confirmed a rectal origin of the tumor. Review of the literature revealed 20 cases of GISTs occurring in the prostate gland, either diagnosed as either primary GISTs or, more commonly, as rectal neoplasms extending to this organ. We add our case in this short list, emphasizing on the importance of inclusion of GISTs in the differential diagnosis of every spindle cell lesion encountered in the prostate.

[Hereditary and non-hereditary syndromic gastointestinal stromal tumours]

The majority of gastrointestinal stromal tumours (GISTs) present as solitary gastrointestinal masses in adults aged 50-70 years. A small subset of GISTs (≤5%) occurs in the setting of familial or idiopathic multitumour syndrome. In decreasing order of frequency, neurofibromatosis Recklinghausen (NF-1), Carney triad (gastric GIST, pulmonary chondroma and extra-adrenal paraganglioma), familial GIST syndromes resulting from germline mutations in c-Kit/PDGFRA and the Carney-Stratakis syndrome (hereditary GIST paraganglioma syndrome caused by germline mutations in the mitochondrial tumour suppressor gene pathway involving the succinate dehydrogenase subunits SDHD, SDHC and SDHB) represent the four most important GIST syndromes characterized to date. Since affected patients and their family members require special treatment and/or counseling and follow-up, early diagnosis and precise classification of this likely still underdiagnosed diseases is of the utmost importance. This review summarizes the pertinent clinicopathological and molecular features of the main GIST syndromes to facilitate their diagnosis and distinction from their non-syndromic mimics.

Radiation induced early necrosis in patients with malignant gliomas receiving temozolomide

BACKGROUND

Temozolomide is the major drug in the treatment of malignant gliomas. Radiation induced necrosis can behave radiologically and clinically like a recurrent tumor. The major problem is the differentiation between recurrence and radiation injury especially in early phases of treatment. The aim of this study was to evaluate the patients receiving temozolomide showing early clinical or radiological progression and impact of early necrosis on follow-up.

PATIENTS AND METHODS

We retrospectively evaluated medical records of 67 patients with malignant glioma receiving temozolomide. All patients received concomitant radiotherapy and temozolomide followed by adjuvant temozolomide. In case of any radiological or clinical progression, MRI spectroscopy evaluation was used to confirm tumoral progression.

RESULTS

Radiological or clinical progression was observed in 17 (25.4%) patients. Early radiation induced necrosis was diagnosed in 4 of 17 patients (23.5%) by surgery (n=3) and MRI spectroscopy (n=1). The observed incidence of pseudoprogression was 4 in 67 (6%) patients. Patients with diagnosis of early radiation injury had median progression-free survival of 7 months compared to 5 months in patients without radiation damage (p=0.004). However, there was no statistically significant difference in terms of overall survival between groups.

CONCLUSION

Temozolomide can cause early radiation induced injury which can mimic progressive tumor. Although the discrimination between two entities results in the accurate evaluation of response to therapy and benefits those patients, it did not affect overall survival. MRI spectroscopy is a valuable tool to define early radiation necrosis and should be further evaluated in larger prospective studies.

Prognostic and predictive value of p53 in low MGMT expressing glioblastoma treated with surgery, radiation and adjuvant temozolomide chemotherapy

OBJECTIVE

To assess the prognostic and predictive significance of p53 protein expression in low O6-methylguanine-DNA methyltransferase (MGMT) expressing glioblastoma multiform (GBM) treated with combined therapy.

METHODS

The authors reviewed the clinical outcomes of 46 low MGMT expressing GBM patients who had undergone surgery, conventional local radiotherapy and temozolomide chemotherapy. Correlation between p53 expression level and clinical outcomes were analysed with univariate and multivariate Cox model.

RESULTS

Patients with low p53 expression had a significantly improved progression free survival (PFS) (p=0.015) and overall survival (OS) (p=0.047) compared to those with high expression. On both univariate and multivariate analyses, low p53 expression persisted as a significant independent favorable prognostic factor for PFS (p=0.017). Pre-operative Karnofsky performance status score (p=0.029), tumor resection extent (p=0.045) and p53 expression level (p=0.038) were significant independent prognostic factors for OS.

CONCLUSION

In these low MGMT expressing GBM patients with combined treatment, low p53 expression was a significant independent favorable prognostic factor for both PFS and OS. In addition to MGMT, p53 may be another stratification variable in the future therapeutic trials.

Molecularly targeted therapies for malignant gliomas

This review critically evaluates current knowledge of molecularly targeted therapies of malignant gliomas.Various molecularly targeted single-agent therapies, including targeted therapies of growth and survival, have been evaluated in clinical trials but have failed to demonstrate a significant survival benefit compared with standard treatment regimens. The efficacy of multitargeted kinase inhibitors or combinations of single-targeted kinase inhibitors is a promising strategy, but requires additional clinical evaluation before definitive conclusions can be made. Important areas for further research include the assessment of serum or tissue biomarkers, the elucidation of prognostic molecular markers, and the determination of whether the mechanism of action of a drug is appropriate to the genetic alterations observed within individual tumors.