Free Fibula Reconstruction for Bone Tumors Involving Humerus: Our Experience

Background Malignant primary bone tumors constitute only 0.2% of all malignancies in adults and approximately 5% of childhood malignancies. The humerus is a common site for malignancies like chondrosarcoma, osteosarcoma, Ewing sarcoma, and metastatic carcinomas. Management consists of multimodality treatment including chemotherapy, radiotherapy, and surgery depending on histology of the tumor and response to therapy. Reconstruction of humerus following oncological resection is a challenging procedure and the surgical options include endoprosthesis, plates, avascular bone grafts, and vascularized autologous bone using microvascular surgery.

Materials and Methods This was a single institutional, retrospective observational study conducted at a tertiary cancer center in Northeast India from June 2018 to March 2020. All the reconstructions were done with free fibular osseous flap. Postoperative outcome was measured with Musculoskeletal Tumor Society (MSTS) scoring. Data was collected from patient records and hospital online reporting system. All data were analyzed using Statistical Package for Social Sciences, version 21. Histograms were used for descriptive statistics; Spearman's correlation was run to determine the relationship between MSTS score and age. Rest of the data was checked with Mann–Whitney and Kruskal–Wallis test. A p-value less than 0.05 was considered as statistically significant at 5% level of significance.

Results Six patients were included in our study (n = 6), three of Ewing sarcoma and one each of osteosarcoma, angiosarcoma, and chondrosarcoma. Mean age was 21.7 ± 18.6 years; there was no flap necrosis in the series. One old lady developed nonunion and fracture at the native humerus in follow-up. At the end of 1 year the mean MSTS score of the series was 24.7/30. From data analysis a significant decrease in mean MSTS score was by 0.134 times (p = 0.035), been observed with increasing age. The correlation between gender and MSTS score (p = 0.325), type of tumor and MSTS score (p = 0.490), and location of the tumor and MSTS score (p = 0.351) was statistically not significant.

Conclusion Free vascularized fibular graft is an important option for bony reconstruction following tumor resection. In our small series we find it very effective for reconstruction of proximal humerus, particularly in younger patients, when microvascular expertise is present. Following a positive initial experience in humerus reconstruction with free fibular osseus flap a large study population will be considered in near future.

Correction to: An Initial Experience of Shoulder Resections and Reconstruction for Bone Tumours from a Cancer Centre in North-East India

[This corrects the article DOI: 10.1007/s13193-021-01292-x.].

Postoperative pancreatic fistulas after pancreaticoduodenectomy for malignancy: A Northeast Indian tertiary cancer center study

Background and Aim

Postoperative pancreatic fistula (POPF) is an important cause of major morbidity and mortality after pancreaticoduodenectomy. We intend to estimate the incidence and study the risk factors and outcomes of patients who developed this dreaded complication.

Methods

This is a retrospective observational study. We included all patients who underwent pancreaticoduodenectomy at a specialized surgical unit of a single tertiary care cancer center in Northeast India. The period of study was from 23 April 2012 to 27 December 2019. The 2016 update on the definition of POPF by the International Study Group for Pancreatic Fistula was used to define the complication. Chi‐square test and Fischer's exact test were applied to categorical variables. t‐test was used to quantify mean difference among continuous variables. P value <0.05 was considered statistically significant at 95% confidence interval.

Results

A total of 59 patients underwent pancreaticoduodenectomy during the study period with almost equal distribution among males and females (29 and 30 patients respectively). The mean age of the patients was 54.0 years (range 20–72). Grade A, B, and C pancreatic fistulas were seen in five (8.5%), three (5.1%), and two (3.4%) patients, respectively. Preoperative hyperbilirubinemia, pancreatic duct size ≤3 mm, hypoalbuminemia, preoperative biliary decompression, and prolonged duration of surgery were identified as risk factors for POPF. POPF also resulted in increased 90‐day mortality (20%).

Conclusion

POPF remains a potentially life‐threatening complication of pancreaticoduodenectomies. The knowledge and management of modifiable risk factors for this condition may help in mitigating this problem.

Reconstruction of Brachial Artery with Great Saphenous Vein Graft in A Case of Residual Soft Tissue Sarcoma Arm

Soft tissue sarcomas of the upper extremities are very rare tumors. Due to the complex anatomy of the arm, the management of the soft tissue sarcoma becomes very challenging for the operating surgeons. Nonetheless, a large portion of the patients can be treated in a limb-sparing manner ,if surgical expertises are present .We report a case of 30 years old lady with soft tissue sarcoma of right arm operated in an another hospital, came to our institute with pain in the operated site and positive histological margins. The patient had feeble radial and ulnar artery pulses. We had done a MR angiography of that limb and it showed no flow from mid arm level in the brachial artery, but presence of collaterals around elbow joint. We had removed the residual tumor and also excised 14 cm of right brachial artery. On opening the brachial artery, tumor thrombus was seen along the whole length of the excised segment. The defect was reconstructed with reverse great saphenous vein graft taken from left leg. Post-operative period was uneventful. Doppler ultrasonography done at 6 and 12 months later showed good flow in the grafted segment with minimal narrowing of the anastomosis sites.

Can Surgical Apgar Score (SAS) Predict Postoperative Complications in Patients Undergoing Gynecologic Oncological Surgery?

Surgeons constantly try to achieve optimal surgical outcome, number, or extent of postoperative complications being an important part of it. Oncological surgeries are conventionally more challenging and complex compared with most nononcological ones. Gawande et al. devised SAS in 2007 in Boston as a predictor tool for postoperative complications (J Am Coll Surg 204:201-208, 2007). A validation study was done by in another cohort of 100 patients; however, only 70% of them had pathologically confirmed malignancies (Ann Surg 240(2):205-213, 2004). We attempt to assess SAS as a tool to predict postoperative complications in a series of 100 gynecological oncological patients operated at tertiary care center. SAS score of 100 patients with gynecologic malignancies, undergoing surgery at a tertiary care center, was prospectively collected over 4 years. These patients were observed for development of any complications occurring up to 30 days postsurgery. The complication events were graded as per Clavien-Dindo classification (Indian J Gynecol Oncolog 15:49, 2017). The data obtained was statistically analyzed by chi-square test. Thirty complication events were recorded in these 100 patients over a period of 4 years. Majority of complication events were grade IIIa or less (22 out of 30); there was only one death on 8th postoperative day. Fifty percent of patients were with SAS score of 5 or less developed complications compared with just 22.9% in patients with a score of 6 or more. Lower SAS score might be associated with higher postoperative complications in patients undergoing gynecologic oncological surgeries. Thus, patients with lower scores may benefit from a triage to more intensive postoperative care.

DNA aptamer probes for detection of estrogen receptor α positive carcinomas

Estrogen receptor alpha (ERα) also known as NR3A1 (nuclear receptor subfamily 3, group A, member 1) is a ligand-activated transcription factor. It is an important biomarker for breast cancer metastasis. In the present study, we report a novel DNA aptamer candidate against estrogen receptor (ER) alpha structure. The enriched aptamer candidate was obtained after 14 iterative cycles of in vitro protein-SELEX process. Isothermal calorimetry study suggests the nanomolar sensitivity of the candidate ER_Apt1 to its target protein. Fluorescence- and chemiluminescence-binding assays confirm the specificity of the candidate aptamer to ER alpha positive breast cancer cell line. Comparative analysis of ER_Apt1 to ER alpha monoclonal antibody was also performed to analyze the expression of ER alpha in various malignant cancer cell line. Cytochemical and immunohistochemistry assay indicates its potential use as a diagnostic agent against ERα positive carcinomas. The nucleotide aptamer sequences described in the present study can be used for the detection, treatment, prophylaxis and diagnosis of ERα-related disorder.

Selection of DNA aptamers for extra cellular domain of human epidermal growth factor receptor 2 to detect HER2 positive carcinomas

BACKGROUND

Human epidermal growth factor receptor 2 (Her2, an orphan receptor of ErbB family) is considered as an important biomarker as it plays a key role in the development and progression of aggressive types of breast, ovarian, stomach and gastric cancer. In the present study, we developed novel DNA aptamers against the extra-cellular domain (ECD) of Her2 protein for detection of Her2-positive carcinomas.

METHODS

We cloned and expressed Her2-ECD protein in E. coli system. After purification, the protein was used as a bait for screening of specific DNA aptamer candidate from a pool of 10^14-15 random oligonucleotides through in vitro Systematic Evaluation of Ligands by Exponential Enrichment (SELEX) process. The aptamer-protein binding kinetics was elucidated by isothermal calorimetry. The specificity of FAM-labelled ECD_Apt1 towards Her2-positive cell lines was estimated by FACS and immunofluorescence assay. The specificity of the candidate was also verified with the tissue samples of breast cancer patients by immunohistochemistry process.

RESULTS

Among four selected candidates, ECD_Apt1 (having minimum ∆G = -3.24) showed the highest binding affinity (K _d = 6.33 ± 0.86 nM) to Her2-ECD protein. The aptamer-protein sandwich assay showed a linear rise in chemiluminescence (at 490 nm wavelength) in the dynamic range of 100-700 nM ECD_Apt1 with a detection limit of 12.5 ± 2.5 ng/mL. Biotinylated ECD_Apt1 showed stronger cytoplasmic staining in Her2-positive breast cancer cell lines (SKBR3) compared to Her2-negative cells (MDA MB 231, MCF7). In paraffin-embedded breast cancer tissue sections, it showed specific and selective localization in the cytoplasmic niche of malignant duct cancer cells without any cross-reactivity to fibroblasts, inflammatory cells and adipocytes.

CONCLUSIONS

Binding assays, cytochemical and histochemical studies support ECD_Apt1 as a potential theranostic agent for Her2-positive carcinomas. ECD_Apt1 could be an effective low-cost alternative to conventional anti-Her2 antibody in solid phase immunoassays for cancer diagnosis and related applications.

Aptamer-Assisted Detection of the Altered Expression of Estrogen Receptor Alpha in Human Breast Cancer

An increase in the expression of estrogen receptors (ER) and the expanded population of ER-positive cells are two common phenotypes of breast cancer. Detection of the aberrantly expressed ERα in breast cancer is carried out using ERα-antibodies and radiolabelled ligands to make decisions about cancer treatment and targeted therapy. Capitalizing on the beneficial advantages of aptamer over the conventional antibody or radiolabelled ligand, we have identified a DNA aptamer that selectively binds and facilitates the detection of ERα in human breast cancer tissue sections. The aptamer is identified using the high throughput sequencing assisted SELEX screening. Biophysical characterization confirms the binding and formation of a thermodynamically stable complex between the identified DNA aptamer (ERaptD4) and ERα (Ka = 1.55±0.298×10⁸ M^-1; ΔH = 4.32×10⁴±801.1 cal/mol; ΔS = -108 cal/mol/deg). Interestingly, the specificity measurements suggest that the ERaptD4 internalizes into ERα-positive breast cancer cells in a target-selective manner and localizes specifically in the nuclear region. To harness these characteristics of ERaptD4 for detection of ERα expression in breast cancer samples, we performed the aptamer-assisted histochemical analysis of ERα in tissue samples from breast cancer patients. The results were validated by performing the immunohistochemistry on same samples with an ERα-antibody. We found that the two methods agree strongly in assay output (kappa value = 0.930, p-value <0.05 for strong ERα positive and the ERα negative samples; kappa value = 0.823, p-value <0.05 for the weak/moderate ER+ve samples, n = 20). Further, the aptamer stain the ERα-positive cells in breast tissues without cross-reacting to ERα-deficient fibroblasts, adipocytes, or the inflammatory cells. Our results demonstrate a significant consistency in the aptamer-assisted detection of ERα in strong ERα positive, moderate ERα positive and ERα negative breast cancer tissues. We anticipate that the ERaptD4 aptamer targeting ERα may potentially be used for an efficient grading of ERα expression in cancer tissues.