Survival and prognostic association in stage IV colorectal cancer patients treated with chemotherapy in Bangladesh.

OBJECTIVE: Prognostic factors in colorectal cancer have lesser been evaluated in developing countries. This study aims to determine overall survival and prognostic factors for metastatic colorectal cancer patients who were non-operable and received chemotherapy. METHODS: The study retrospectively investigated 67 inoperable metastatic colorectal cancer patients at Square Hospital, Bangladesh. The primary endpoint was overall survival, and the secondary endpoints were prognostic association with factors. Survival probabilities were calculated by non-parametric Kaplan-Meier method and compared by log-rank test. Univariate and multivariable Cox proportional hazard models were implemented to assess the prognostic association. RESULTS: Median survival of the entire cohort was 14 months (95% confidence interval: 11-25). In multivariable analysis, two prognostic factors were independently associated with survival: Karnofsky performance status and carcinoembryonic antigen. Patients with Karnofsky performance status <70 had significant higher risk of death than those with Karnofsky performance status ≥70 (adjusted hazard ratio 4.25, 95% confidence interval: 2.15-8.39). Higher risk of death was found to be associated with higher carcinoembryonic antigen: adjusted hazard ratio was 1.72 (95% confidence interval: 0.81-3.68) and 2.96 (95% confidence interval: 1.25-7.01) for patients with carcinoembryonic antigen 10-100 and >100 ng/ml, respectively, while comparing with carcinoembryonic antigen <10 ng/ml. The presence of peritoneal metastasis and grade-III tumour significantly worsened the survival in univariate analysis (hazard ratio 2.46, 95% confidence interval: 1.32-4.57 and hazard ratio 1.74, 95% confidence interval: 1.01-3.03, respectively) but not in multivariable analysis (adjusted hazard ratio 1.92, 95% confidence interval: 0.88-4.18 and adjusted hazard ratio 1.25, 95% confidence interval: 0.66-2.36, respectively). CONCLUSION: The study reported survival of stage IV colorectal cancer patients undergo chemotherapy and identified that Karnofsky performance status and carcinoembryonic antigen are the poor prognostic factors to this cohort adjusting for other factors.

Unusual primary breast cancer - malignant peripheral nerve sheath tumor: a case report and review of the literature.

BACKGROUND: Sarcomas are a rare type of breast malignancies and malignant peripheral nerve sheath tumors of the breast are even rarer. There are no specific clinical and radiological features for the diagnosis of this tumor and histological features are also reported to be nonspecific. Therefore, immunohistochemistry is required for its diagnosis. A definitive treatment protocol is unavailable because of its rarity. CASE PRESENTATION: We report a case of a sporadic form of breast malignant peripheral nerve sheath tumor found in a 16-year-old Asian Bangladeshi girl. She experienced local recurrence and she had multiple left breast lumps four times in a very short period after repeated surgeries. However, she was later managed successfully with chemotherapy and locoregional radiotherapy. A chemotherapy protocol with ifosfamide, vincristine, and actinomycin was used and radiotherapy was given with a total dose of 50 Gy given in 25 fractions of 2 Gy by a 6 MV photon linear accelerator followed by 10 Gy boost given in 5 fractions of 2 Gy by 9 MeV electron energy. With more than 3 years of periodic follow-up, she is still well without any locoregional and metastatic recurrence. CONCLUSIONS: This report suggests proper immunohistochemical analysis whenever a breast sarcoma is found in order to find a rare histological variety. We believe that malignant peripheral nerve sheath tumor of the breast can be managed by total mastectomy followed by adjuvant chemotherapy and radiotherapy. Long-term meticulous follow-up is required to develop an optimum therapeutic strategy.

Comparative molecular cytogenetic analyses of a major tandemly repeated DNA family and retrotransposon sequences in cultivated jute Corchorus species (Malvaceae).

BACKGROUND AND AIMS: The cultivated jute species Corchorus olitorius and Corchorus capsularis are important fibre crops. The analysis of repetitive DNA sequences, comprising a major part of plant genomes, has not been carried out in jute but is useful to investigate the long-range organization of chromosomes. The aim of this study was the identification of repetitive DNA sequences to facilitate comparative molecular and cytogenetic studies of two jute cultivars and to develop a fluorescent in situ hybridization (FISH) karyotype for chromosome identification. METHODS: A plasmid library was generated from C. olitorius and C. capsularis with genomic restriction fragments of 100-500 bp, which was complemented by targeted cloning of satellite DNA by PCR. The diversity of the repetitive DNA families was analysed comparatively. The genomic abundance and chromosomal localization of different repeat classes were investigated by Southern analysis and FISH, respectively. The cytosine methylation of satellite arrays was studied by immunolabelling. KEY RESULTS: Major satellite repeats and retrotransposons have been identified from C. olitorius and C. capsularis. The satellite family CoSat I forms two undermethylated species-specific subfamilies, while the long terminal repeat (LTR) retrotransposons CoRetro I and CoRetro II show similarity to the Metaviridea of plant retroelements. FISH karyotypes were developed by multicolour FISH using these repetitive DNA sequences in combination with 5S and 18S-5·8S-25S rRNA genes which enable the unequivocal chromosome discrimination in both jute species. CONCLUSIONS: The analysis of the structure and diversity of the repeated DNA is crucial for genome sequence annotation. The reference karyotypes will be useful for breeding of jute and provide the basis for karyotyping homeologous chromosomes of wild jute species to reveal the genetic and evolutionary relationship between cultivated and wild Corchorus species.

Comparative molecular cytogenetics of major repetitive sequence families of three Dendrobium species (Orchidaceae) from Bangladesh.

BACKGROUND AND AIMS: Dendrobium species show tremendous morphological diversity and have broad geographical distribution. As repetitive sequence analysis is a useful tool to investigate the evolution of chromosomes and genomes, the aim of the present study was the characterization of repetitive sequences from Dendrobium moschatum for comparative molecular and cytogenetic studies in the related species Dendrobium aphyllum, Dendrobium aggregatum and representatives from other orchid genera. METHODS: In order to isolate highly repetitive sequences, a c(0)t-1 DNA plasmid library was established. Repeats were sequenced and used as probes for Southern hybridization. Sequence divergence was analysed using bioinformatic tools. Repetitive sequences were localized along orchid chromosomes by fluorescence in situ hybridization (FISH). KEY RESULTS: Characterization of the c(0)t-1 library resulted in the detection of repetitive sequences including the (GA)(n) dinucleotide DmoO11, numerous Arabidopsis-like telomeric repeats and the highly amplified dispersed repeat DmoF14. The DmoF14 repeat is conserved in six Dendrobium species but diversified in representative species of three other orchid genera. FISH analyses showed the genome-wide distribution of DmoF14 in D. moschatum, D. aphyllum and D. aggregatum. Hybridization with the telomeric repeats demonstrated Arabidopsis-like telomeres at the chromosome ends of Dendrobium species. However, FISH using the telomeric probe revealed two pairs of chromosomes with strong intercalary signals in D. aphyllum. FISH showed the terminal position of 5S and 18S-5.8S-25S rRNA genes and a characteristic number of rDNA sites in the three Dendrobium species. CONCLUSIONS: The repeated sequences isolated from D. moschatum c(0)t-1 DNA constitute major DNA families of the D. moschatum, D. aphyllum and D. aggregatum genomes with DmoF14 representing an ancient component of orchid genomes. Large intercalary telomere-like arrays suggest chromosomal rearrangements in D. aphyllum while the number and localization of rRNA genes as well as the species-specific distribution pattern of an abundant microsatellite reflect the genomic diversity of the three Dendrobium species.