Depletion of essential fatty acids in muscle is associated with shorter survival of cancer patients undergoing surgery-preliminary report

Emerging studies are reporting associations between skeletal muscle abnormalities and survival in cancer patients. Cancer prognosis is associated with depletion of essential fatty acids in erythrocytes and plasma in humans. However the relationship between skeletal muscle membrane fatty acid composition and survival is unknown. This study investigates the relationship between fatty acid content of phospholipids in skeletal muscle and survival in cancer patients. Rectus abdominis biopsies were collected during cancer surgery from 35 patients diagnosed with cancer. Thin-layer and gas chromatography were used for quantification of phospholipid fatty acids. Cutpoints for survival were defined using optimal stratification. Median survival was between 450 and 500 days when patients had arachidonic acid (AA) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in muscle phospholipid below the cut-point compared to 720-800 days for patients above. Cox regression analysis revealed that low amounts of AA, EPA and DHA are risk factors for death. The risk of death remained significant for AA [HR 3.5 (1.11-10.87), p = 0.03], EPA [HR 3.92 (1.1-14.0), p = 0.04] and DHA [HR 4.08 (1.1-14.6), p = 0.03] when adjusted for sex. Lower amounts of essential fatty acids in skeletal muscle membrane is a predictor of survival in cancer patients. These results warrant investigation to restore bioactive fatty acids in people with cancer.

BIK drives an aggressive breast cancer phenotype through sublethal apoptosis and predicts poor prognosis of ER-positive breast cancer

Apoptosis is fundamental to normal animal development and is the target for many anticancer therapies. Recent studies have explored the consequences of "failed apoptosis" where the apoptotic program is initiated but does not go to completion and does not cause cell death. Nevertheless, this failed apoptosis induces DNA double-strand breaks generating mutations that facilitate tumorigenesis. Whether failed apoptosis is relevant to clinical disease is unknown. BCL-2 interacting killer (BIK) is a stress-induced BH3-only protein that stimulates apoptosis in response to hormone and growth factor deprivation, hypoxia, and genomic stress. It was unclear whether BIK promotes or suppresses tumor survival within the context of breast cancer. We investigated this and show that BIK induces failed apoptosis with limited caspase activation and genomic damage in the absence of extensive cell death. Surviving cells acquire aggressive phenotypes characterized by enrichment of cancer stem-like cells, increased motility and increased clonogenic survival. Furthermore, by examining six independent cohorts of patients (total n = 969), we discovered that high BIK mRNA and protein levels predicted clinical relapse of Estrogen receptor (ER)-positive cancers, which account for almost 70% of all breast cancers diagnosed but had no predictive value for hormone receptor-negative (triple-negative) patients. Thus, this study identifies BIK as a biomarker for tumor recurrence of ER-positive patients and provides a potential mechanism whereby failed apoptosis contributes to cancer aggression.

Lipid is heterogeneously distributed in muscle and associates with low radiodensity in cancer patients

BACKGROUND

Low muscle radiodensity is associated with mortality in a variety of cancer types. Biochemical and morphological correlates are unknown. We aimed to evaluate triglyceride (TG) content and location as a function of computed tomography (CT)-derived measures of skeletal muscle radiodensity in cancer patients.

METHODS

Rectus abdominis (RA) biopsies were collected during cancer surgery from 75 patients diagnosed with cancer. Thin-layer chromatography and gas chromatography were used for quantification of TG content of the muscle. Axial CT images of lumbar vertebra were used to measure muscle radiodensity. Oil Red O staining was used to determine the location of neutral lipids in frozen muscle sections.

RESULTS

There was wide variation in RA radiodensity in repeated measures (CV% ranged from 3 to 55% based on 10 serial images) as well as within one slice (CV% ranged from 6 to 61% based on 10 subregions). RA radiodensity and total lumbar muscle radiodensity were inversely associated with TG content of RA (r = -0.396, P < 0.001, and r = -0.355, P = 0.002, respectively). Of the total percentage area of muscle staining positive for neutral lipid, 54 ± 17% was present as extramyocellular lipids (range 23.5-77.8%) and 46 ± 17% (range 22.2-76.5%) present as intramyocellular lipid droplets.

CONCLUSIONS

Repeated measures revealed wide variation in radiodensity of RA muscle, both vertically and horizontally. Low muscle radiodensity reflects high level of TG in patients with cancer. Non-uniform distribution of intramyocellular and extramyocellular lipids was evident using light microscopy. These results warrant investigation of mechanisms resulting in lipid deposition in muscles of cancer patients.

Clinical and biological characterization of skeletal muscle tissue biopsies of surgical cancer patients

BACKGROUND

Researchers increasingly use intraoperative muscle biopsy to investigate mechanisms of skeletal muscle atrophy in patients with cancer. Muscles have been assessed for morphological, cellular, and biochemical features. The aim of this study was to conduct a state-of-the-science review of this literature and, secondly, to evaluate clinical and biological variation in biopsies of rectus abdominis (RA) muscle from a cohort of patients with malignancies.

METHODS

Literature was searched for reports on muscle biopsies from patients with a cancer diagnosis. Quality of reports and risk of bias were assessed. Data abstracted included patient characteristics and diagnoses, sample size, tissue collection and biobanking procedures, and results. A cohort of cancer patients (n = 190, 88% gastrointestinal malignancies), who underwent open abdominal surgery as part of their clinical care, consented to RA biopsy from the site of incision. Computed tomography (CT) scans were used to quantify total abdominal muscle and RA cross-sectional areas and radiodensity. Biopsies were assessed for muscle fibre area (μm² ), fibre types, myosin heavy chain isoforms, and expression of genes selected for their involvement in catabolic pathways of muscle.

RESULTS

Muscle biopsy occurred in 59 studies (total N = 1585 participants). RA was biopsied intraoperatively in 40 studies (67%), followed by quadriceps (26%; percutaneous biopsy) and other muscles (7%). Cancer site and stage, % of male participants, and age were highly variable between studies. Details regarding patient medical history and biopsy procedures were frequently absent. Lack of description of the population(s) sampled and low sample size contributed to low quality and risk of bias. Weight-losing cases were compared with weight stable cancer or healthy controls without considering a measure of muscle mass in 21 out of 44 studies. In the cohort of patients providing biopsy for this study, 78% of patients had preoperative CT scans and a high proportion (64%) met published criteria for sarcopenia. Fibre type distribution in RA was type I (46% ± 13), hybrid type I/IIA (1% ± 1), type IIA (36% ± 10), hybrid type IIA/D (15% ± 14), and type IID (2% ± 5). Sexual dimorphism was prominent in RA CT cross-sectional area, mean fibre cross-sectional area, and in expression of genes associated with muscle growth, apoptosis, and inflammation (P < 0.05). Medical history revealed multiple co-morbid conditions and medications.

CONCLUSIONS

Continued collaboration between researchers and cancer surgeons enables a more complete understanding of mechanisms of cancer-associated muscle atrophy. Standardization of biobanking practices, tissue manipulation, patient characterization, and classification will enhance the consistency, reliability, and comparability of future studies.

Immunohistochemical phenotyping of T cells, granulocytes, and phagocytes in the muscle of cancer patients: association with radiologically defined muscle mass and gene expression

BACKGROUND

Inflammation is a recognized contributor to muscle wasting. Research in injury and myopathy suggests that interactions between the skeletal muscle and immune cells confer a pro-inflammatory environment that influences muscle loss through several mechanisms; however, this has not been explored in the cancer setting. This study investigated the local immune environment of the muscle by identifying the phenotype of immune cell populations in the muscle and their relationship to muscle mass in cancer patients.

METHODS

Intraoperative muscle biopsies were collected from cancer patients (n = 30, 91% gastrointestinal malignancies). Muscle mass was assessed histologically (muscle fiber cross-sectional area, CSA; μm²) and radiologically (lumbar skeletal muscle index, SMI; cm²/m² by computed tomography, CT). T cells (CD4 and CD8) and granulocytes/phagocytes (CD11b, CD14, and CD15) were assessed by immunohistochemistry. Microarray analysis was conducted in the muscle of a second cancer patient cohort.

RESULTS

T cells (CD3+), granulocytes/phagocytes (CD11b+), and CD3-CD4+ cells were identified. Muscle fiber CSA (μm²) was positively correlated (Spearman's r = > 0.45; p = < 0.05) with the total number of T cells, CD4, and CD8 T cells and granulocytes/phagocytes. In addition, patients with the smallest SMI exhibited fewer CD8 T cells within their muscle. Consistent with this, further exploration with gene correlation analyses suggests that the presence of CD8 T cells is negatively associated (Pearson's r = ≥ 0.5; p = <0.0001) with key genes within muscle catabolic pathways for signaling (ACVR2B), ubiquitin proteasome (FOXO4, TRIM63, FBXO32, MUL1, UBC, UBB, UBE2L3), and apoptosis/autophagy (CASP8, BECN1, ATG13, SIVA1).

CONCLUSION

The skeletal muscle immune environment of cancer patients is comprised of immune cell populations from the adaptive and innate immunity. Correlations of T cells, granulocyte/phagocytes, and CD3-CD4+ cells with muscle mass measurements indicate a positive relationship between immune cell numbers and muscle mass status in cancer patients. Further exploration with gene correlation analyses suggests that the presence of CD8 T cells is negatively correlated with components of muscle catabolism.

Comparison and clinical implementation of quality of life tools in patients with small bowel neuroendocrine tumors treated with Lu-DOTA-TATE PRRT

Aim: This study assesses if clinically developed quality of life (QoL) tools are as effective in small bowel neuroendocrine tumors (NETs) as NET-specific research questionnaires. Methods: QoL in patients with small bowel NETs treated with Lu-DOTA-TATE was assessed with The European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30, QLQ-GI.NET21 and Edmonton Symptom Assessment System Revised (ESAS-r) at baseline and after four treatments. Repeated measures ANOVA was performed. Results: Both EORTC and ESAS-r demonstrated maintained overall QoL. EORTC demonstrated statistically and clinically significant improvement in insomnia, diarrhea, gastrointestinal, endocrine symptoms and social function. ESAS-r demonstrated statistically and clinically significant improvement in overall total symptom distress score. Conclusion: ESAS-r is quick and easy to interpret. It is not as sensitive to individual symptoms but does track overall function. EORTC assessment is more complex, but better reflects QoL for NET specific symptoms.

A population-based study of outcomes in patients with gastrointestinal neuroendocrine tumours

BACKGROUND

Neuroendocrine tumours (NETs) are heterogeneous, with varying presentations and treatment options. To our knowledge, there are no randomized and few long-term studies of patient outcomes. The role of surgical and medical therapy for local, regional and metastatic disease continues to be evaluated in the literature.

METHODS

We conducted a population-based search of the provincial cancer registry to identify patients with gastrointestinal NETs from the stomach, small intestine, colon and rectum diagnosed between 1990 and 2005 and assessed their outcomes.

RESULTS

We examined clinicopathological information on the outcomes of 530 patients with gastrointestinal NETs. The overall incidence of NETs increased from 11 per million to 19 per million during the study period. Advancing stage and patient age were associated with poor overall or disease-specific outcomes. Surgery, both curative and palliative, was associated with decreased risk of overall (hazard ratio [HR] 0.5, p < 0.001) and disease-specific (HR 0.5, p < 0.001) death. The biggest benefit was observed in patients with distant disease, in whom 5-year disease-specific survival for R0 resections was nearly double that for patients with macroscopic residual disease (92% v. 48%, p = 0.009). Older age was associated with poor 5-year overall and disease-specific survival (p < 0.001).

CONCLUSION

There has been a significant increase in incidence of gastrointestinal NETs, and advancing patient age, but not sex, is linked to poor outcomes in terms of overall and disease-specific survival. Surgery, both curative and palliative, was associated with decreased risk of overall and disease-specific death. Compared with patients with residual macroscopic disease, patients with distant disease were nearly twice as likely to survive 5 years if they had R0 resections. The use of radioisotope therapy and long-acting octreotide therapy was also associated with improved outcomes overall.

Excision of middle mediastinal parathyroid adenoma by videoscopic assisted mediastinoscopy (VAM)

We report a case involving a female patient with primary hyperparathyroidism arising from a middle mediastinal parathyroid adenoma. Initial diagnosis was made based on a history of polyuria and recurrent renal colic. At the age of 77 she underwent videoscopic assisted mediastinoscopy (VAM) for resection of the adenoma which was localized using single-photon emission computed tomography (SPECT/CT). This case illustrates the importance for accurate pre-operative localization and intra-operative monitoring to ensure complete surgical removal in order to improve postoperative normocalcemia success rates.

Platelet-derived growth factor receptor-α promotes lymphatic metastases in papillary thyroid cancer

Lymph node metastases are common in papillary thyroid cancer (PTC) and can be resistant to surgical extirpation or radioiodine ablation. We examined the role of platelet-derived growth factor receptor (PDGFR) in mediating lymph node metastases in PTC. Clinical specimens of PTC (n = 137) were surveyed in a tissue array and by western blots to examine the relationship between expression of the α and β subunits of PDGFR and lymph node metastases. PDGFR-α was found at high levels in primary tumours with known lymphatic metastases but not in those tumours lacking nodal involvement (p < 0.0001). However, PDGFR-β expression was not linked to metastatic disease (p = 0.78) as it was found in virtually all PTC specimens. A matching analysis in fresh PTC specimens (n = 13) confirmed that PDGFR-α expression was strongly linked to metastatic spread (p = 0.0047). PDGFR-α and -β were not found in normal thyroid tissue (p < 0.0001). PTC cell lines selectively expressing PDGFR-α or -β were assessed for invasive potential and activation of downstream signal transduction pathways. PTC cell lines expressing PDGFR-α responded to PDGF-BB stimulation with increased invasive potential and this process can be blocked by the tyrosine kinase receptor inhibitor sunitinib (p < 0.009). Cell lines with only PDGFR-β, or no PDGFR, did not show significant changes in invasive potential. Activation of PDGFR-α led to downstream up-regulation of both the MAPK/ERK and PI3K/Akt pathways and disruption of either pathway is sufficient to block PDGFR-mediated increases in invasive potential. Thus, PDGFR-α is associated with lymph node metastases in papillary thyroid carcinoma and PDGFR-α promotes increased invasive potential in PTC cell lines. PDGFR-α is a strong candidate for a diagnostic biomarker to identify patients at risk of nodal metastases. Our results also strengthen the rationale for selection of tyrosine kinase receptor inhibitors that target PDGFR in the treatment of progressive, metastatic PTC.

Upregulation of the signal transducers and activators of transcription 3 (STAT3) pathway in lymphatic metastases of papillary thyroid cancer

Papillary thyroid cancer (PTC) has an impressive propensity for lymphatic spread. Signal transducers and activators of transcription 3 (STAT3), constitutively activated in many different cancers, may play a role in PTC lymphatic metastases. We examined 49 patients with PTC, 22 with and 27 without lymphatic metastases. All patients had a total thyroidectomy with lymph node dissection to document true node negative cases. The level of STAT3 expression in benign, non-neoplastic thyroid tissue is barely detectable by immunohistochemistry. Only 11 of the 35 (31%) specimens exhibited weak immunostainingfor STAT3 and pSTAT3 was found weakly positive in 3 of 35 (9%) benign specimens. Expression of STAT3 in all PTC primary tumors was 98% (40/41) and thus significantly higher than corresponding benign thyroid tissue (p=0.0001). pSTAT3 was found in 37% of primary tumors (15/41) and this was significantly higher than pSTAT3 expression in benign tissue (p=0.006). Comparing node-positive and node-negative primary tumors, there was no difference in staining intensity for STAT3 where strong (2+) staining was seen 12/19 node-positive tumors and 13/22 node-negative tumors (p=1). Regarding pSTAT3 expression in primary PTC tumors, node negative cases (n=22) exhibited significantly less staining compared to node positive cases (n=19). Only 4 of 22 (18%) cases in the node-negative group were weakly (1+) positive for pSTAT3 while 12 of 19 (58%) cases in the node-positive group were positive (p=0.011) with 45% of these specimens exhibiting strong (2+) staining. Lymphatic metastases were highly positive (>93%) for both STAT3 and pSTAT3. The STAT3 pathway is ubiquitous in PTC and activated pSTAT3 is significantly upregulated in PTC tumors with metastatic disease. This study is the first to suggest a potential role for activated pSTAT3 in lymphatic metastases in thyroid cancer.

Presentation of clinically solitary thyroid nodules in surgical patients

BACKGROUND

Thyroid nodules occupy a unique position in relation to clinical diagnosis since most patients with a thyroid nodule do not present with overt symptoms. There are, however, no good published data demonstrating the way in which clinically solitary thyroid nodules come to medical attention, with most of the literature being anecdotal. This study aims to evaluate the mode of presentation of solitary thyroid nodules, and to assess whether the presence of a malignancy influences that presentation.

METHODS

In this retrospective cohort study, data were obtained from the University of Sydney Endocrine Surgery Database and through a review of the patient records. The study cohort comprised 419 consecutive patients who presented with a clinically solitary thyroid nodule and who subsequently underwent surgery. Patient files lacking data on mode of presentation and patients in whom thyroid nodules were incidentally discovered during parathyroid surgery were excluded, leaving a total of 299 patients. Data were analyzed using a computer-based statistical software package. Continuous variables were compared using Student's t-test. Categorical variables were analyzed using Fishers exact test. Statistical significance was set at p < 0.05.

RESULTS

Solitary thyroid nodules are most commonly detected by the patients themselves (40%), followed by the incidental discovery of nodules on imaging studies performed for unrelated reasons (30%), and lastly due to third-party diagnosis by family, friends, acquaintances, or medical practitioners (30%). Nodules detected by medical practitioners were statistically more likely to be malignant (p = 0.02). No other differences between the clinical presentation of benign and malignant nodules were found.

CONCLUSIONS

Patients themselves are the ones who most commonly first become aware of the thyroid nodules that are eventually seen by thyroid surgeons. Incidental discovery on image studies is also important. Thyroid nodules detected by medical practitioners should be dealt with most urgently because they are most likely to be malignant.

Minimally invasive thyroid surgery for single nodules: an evidence-based review of the lateral mini-incision technique

BACKGROUND

Minimally invasive thyroidectomy techniques are being developed in an effort to minimize pain, shorten the length of hospital stay, and improve cosmesis. Various minimally invasive thyroid surgery (MITS) techniques have been shown to be safe and feasible with some benefits in terms of cosmesis and pain outcomes; however, no single technique has been broadly accepted. This study was designed to review the evidence in relation to MITS and our experience with the direct lateral mini-incision technique.

METHODS

A review of literature published until December 2007 on minimally invasive thyroidectomy techniques was undertaken. Three issues were addressed: 1) Does MITS provide any benefit compared with conventional open thyroidectomy? 2) Is there any advantage to the use of endoscopic or video-assisted techniques compared with the direct mini-incision technique? 3) Is the lateral mini-incision technique safe and efficacious? Additional data in relation to the above issues was derived from a retrospective cohort study of patients undergoing mini-incision thyroid surgery within our unit.

RESULTS

Issue 1: Five prospective randomized studies and eight studies at a lower level of evidence have demonstrated consistent advantages of MITS compared with open thyroid surgery in terms of reduced pain and improved cosmesis with equivalent operative safety. Issue 2: In compiling four level III and IV studies that compared open and video-assisted minimally invasive surgery, there do not seem to be significant differences in patient satisfaction with the incision. The video-assisted approaches require significantly longer operative times but also seem to be less painful. Issue 3: Three cohort studies (level IV) have demonstrated that the lateral mini-incision technique is both safe and efficacious compared with open surgery for hemi-thyroidectomy. Data from our cohort study of 1281 patients (open hemi-thyroidectomy 1054 vs. MITS 227) confirmed MITS to be a safe and effective procedure. The rate of postoperative hematoma formation and wound infection was equivalent between groups. The rate of permanent recurrent laryngeal nerve injury was 0.4% for MITS and 0.3% for CHT and not significantly different (p = 0.7).

CONCLUSIONS

MITS has demonstrated advantages over conventional open approaches for both hemi- and total thyroidectomy and the benefits do not depend on the open or video-assisted approach. For thyroid lobectomies, the lateral mini-incision approach can be performed with an operative time and postoperative complication profile equivalent to conventional hemi-thyroidectomy while providing excellent cosmesis with a 2-3 cm scar.

A lattice model for computing the transmissivity of the cornea and sclera

The method of photonic band structure is used to calculate the frequencies of light that propagate in lattice models of the cornea and sclera of the mammalian eye, providing an explanation for transparency in the cornea that first properly accounts for multiple scattering of light. Each eye tissue is modeled as an ordered array of collagen rods, and photonic band structure methods are used to solve Maxwell's equations exactly for these models, a procedure that automatically effectively includes all orders of multiple scattering. These calculations show that the dispersion relation for the cornea is linear in the visible range, implying that the cornea is transparent. We show that the transmissivity is approximately 97% by using an effective medium approximation derived from the photonic band structure results and applicable in the visible region. In contrast, the dispersion relation for the model in the sclera is not linear in the visible region, and there are band gaps in this region that could play an important role in the transmission of light in the sclera.

The consequences of engineering an extra disulfide bond in the Penicillium camembertii mono- and diglyceride specific lipase

The extracellular lipase from Penicillium camembertii has unique substrate specificity restricted to mono- and diglycerides. The enzyme is a member of a homologous family of lipases from filamentous fungi. Four of these proteins, from the fungi Rhizomucor miehei, Humicola lanuginosa, Rhizopus delemar and P. camembertii, have had their structures elucidated by X-ray crystallography. In spite of pronounced sequence similarities the enzymes exhibit significant differences. For example, the thermostability of the P. camembertii lipase is considerably lower than that of the H. lanuginosa enzyme. Since only the P. camembertii enzyme lacks the characteristic long disulfide bridge, corresponding to Cys22-Cys268 in the H. lanuginosa lipase, we have engineered this disulfide into the former enzyme in the hope of obtaining a significantly more stable fold. The properties of the double mutant (Y22C and G269C) were assessed by a variety of biophysical techniques. The extra disulfide link was found to increase the melting temperature of the protein from 51 to 63 degrees C. However, no difference is observed under reducing conditions, indicating an intrinsic instability of the new disulfide. The optimal temperature for catalytic activity decreased by 10 degrees C and the optimum pH was shifted by 0.7 units to more acidic.

Ambulatory Gynecologic Surgery

A retrospective study evaluated the feasibility and safety of operative gynecologic procedures performed in an ambulatory surgical center. Between July 1993 and December 1995, 5766 women (mean age 36.9 yrs, range 13-95 yrs) who were referred to our center underwent surgery. The most common preoperative diagnoses were dysfunctional bleeding, missed abortion, postmenopausal bleeding, cervical dysplasia, mullerian duct malformation, infertility, endometriosis, adhesions, desire for sterilization, adnexal mass, lower abdominal pain, ectopic pregnancy, and fibroids. A total of 2351 laparoscopies, 2 laparotomies, and 3415 vaginal procedures were performed. The most common procedures were dilatation and curettage, 1455; hysteroscopy, 1051; adnexal surgery, 810; tubal ligation, 679; abdominal myomectomy, 186; operative hysteroscopy, 145; and cone biopsy, 118. The duration of surgery was 10 to 210 minutes. Most patients (99.51%) were discharged between 2 and 8 hours after surgery. Only 28 (0.49%) had to be admitted to the hospital; 18 women had preoperatively planned admissions and 10 were unexpectedly admitted postoperatively. The intraoperative and postoperative complication rate was 0.50% (29). We believe that ambulatory surgery is safe and efficient with proper patient selection and when the surgeon and the anesthetist have significant expertise.

The savant syndrome and extrasensory perception

D.A. Treffert, following B. Rimland, cited examples which he states show ESP to be occurring in certain autistic savant children. The evidence is questioned on the ground that it is hearsay, uncorroborated by independent scrutiny.