An Update of Stereotactic Body Radiotherapy (SBRT) for the Palliation of Unirradiated Mucosal Head and Neck Squamous Cell Carcinoma (SCC)

PURPOSE/OBJECTIVE(S)

We report the treatment outcomes of palliative Stereotactic Body Radiation Therapy (SBRT) in patients with primary mucosal head and neck cancer (HNC) who were not eligible to receive conventional radiation therapy (RT).

MATERIALS/METHODS

This is a retrospective study that reviewed the medical records of patients with primary SCC mucosal HNC who were treated with SBRT between 2011 and 2022. Patients with other histologies, skin cancer, parotid tumors, or recurrent previously irradiated tumors were excluded from the study.

RESULTS

A total of 74 patients and 77 tumors were treated with SBRT in this cohort. The median age in the study was 81 (52-97) years and the median follow-up was 7.2 months. The most common site of HNC was the oral cavity (62%), followed by the oropharynx (18%), hypopharynx (8%), larynx (5%), nasal cavity/sinonasal cancer (3%), and unknown primary (1%). T3-4 lesions were found in most patients (76%). SBRT doses ranged from 35-50 Gy in 5 fractions, and the most common prescription dose was ≥45 Gy in 5 fractions (60%) for the GTV prescription. An elective nodal volume of 25 Gy in 5 fractions was infrequently (17%) used. Most patients (81%) who were treated twice a week completed in ≤14 days. The predominant symptoms at presentation were: pain (41%), mass effect (39%), dysphagia/odynophagia (14%), headache/nasal obstruction (1.4%), bleeding (1.4%), stridor (1.4%), asymptomatic (1.4%), and unknown (1.4%). 84% of patients had symptomatic response to treatment with 24% of them having complete symptom response. Cumulative incidence of local failure (LF) was 6.7% and at 6 months and 17.9% at 12 months, respectively. Cumulative incidence of distant metastasis was 7.3% and 10.5% at 6 and 12 months. Cancer was the most common cause of death in 29 patients (51%). The median overall survival (OS) was 8 months with 6 and 12-month OS rates of 67% and 36%, respectively. 39% of patients developed acute G3 toxicity, including 30% with G3 mucositis, 5% with G3 dysphagia, and 4% with G3 dermatitis. A crude rate of late G ≥3 toxicity was observed in 11% of patients including (5%, n = 4) with osteoradionecrosis, and a single case of dysphagia, soft tissue necrosis, supraglottic ulceration, and mucosal necrosis.

CONCLUSION

This study highlights the feasibility of SBRT as a treatment option for primary mucosal head and neck cancer patients who are not eligible for conventional radiation therapy. The results indicate that SBRT was effective in achieving local control and symptom relief, but larger prospective studies are needed to confirm the findings. The Canadian Cancer Trials Group has endorsed HN-13, a randomized control trial comparing HN SBRT to palliative RT.

A-04 Acute Sports-Related Concussion Associations Between Cognitive Symptoms, Memory Performance, and Default Mode Network Hub Connectivity

Purpose: Disruptions in cognitive performance are commonly reported after a sports-related concussion (SRC) and may be related to brain network changes, particularly within the default mode network (DMN). Since well-connected brain regions across networks (hubs) play an important role in network organization, we hypothesize that DMN hubs will be disrupted after a SRC and associated with cognitive symptoms and cognitive performance. Methods: We collected resting-state fMRI, symptoms, and cognitive performance data from 44 student-athletes at baseline, after a SRC, and at recovery. Participation coefficient defined hubs for each athlete. We compared changes in functional connectivity between hubs and non-hubs within the DMN and between DMN hubs and non-hubs in the remaining networks. We used linear regression to examine the relationship between functional connectivity, cognitive symptoms, and cognitive performance while controlling for concussion history. Results: Functional connectivity between hubs and non-hubs within the DMN increased from baseline to post-injury and decreased from post-injury to recovery, but not to baseline connectivity levels. Post-injury functional connectivity was related to increased cognitive symptoms and decreased visual memory performance. Functional connectivity decreased between hubs in the DMN and non-hubs in the cingulo-opercular, salience, somatomotor, and visual networks from baseline to post-injury. Cognitive symptoms and visual memory performance were related to functional connectivity between DMN hubs and visual network non-hubs. Conclusions: Self-reported cognitive symptoms and cognitive performance were associated with changes in DMN hub connectivity. This relationship may suggest a decrease in efficiency between brain networks after a SRC and may provide insight into post-injury compensation during task performance.

Guidelines for the management of diabetes services and patients during the COVID-19 pandemic

The UK National Diabetes Inpatient COVID Response Group was formed at the end of March 2020 to support the provision of diabetes inpatient care during the COVID pandemic. It was formed in response to two emerging needs. First to ensure that basic diabetes services are secured and maintained at a time when there was a call for re-deployment to support the need for general medical expertise across secondary care services. The second was to provide simple safe diabetes guidelines for use by specialists and non-specialists treating inpatients with or suspected of COVID-19 infection. To date the group, comprising UK-based specialists in diabetes, pharmacy and psychology, have produced two sets of guidelines which will be continually revised as new evidence emerges. It is supported by Diabetes UK, the Association of British Clinical Diabetologists and NHS England.

Guidelines for the management of diabetes in care homes during the Covid-19 pandemic

The National Diabetes Stakeholders Covid-19 Response Group was formed in early April 2020 as a rapid action by the Joint British Diabetes Societies for Inpatient Care, Diabetes UK, the Association of British Clinical Diabetologists, and Diabetes Frail to address and support the special needs of residents with diabetes in UK care homes during Covid-19. It was obvious that the care home sector was becoming a second wave of Covid-19 infection and that those with diabetes residing in care homes were at increased risk not only of susceptibility to infection but also to poorer outcomes. Its key purposes included minimising the morbidity and mortality associated with Covid-19 and assisting care staff to identify those residents with diabetes at highest risk of Covid-19 infection. The guidance was particularly created for care home managers, other care home staff, and specialist and non-specialist community nursing teams. The guidance covers the management of hyperglycaemia by discussion of various clinical scenarios that could arise, the management of hypoglycaemia, foot care and end of life care. In addition, it outlines the conditions where hospital admission is required. The guidance should be regarded as interim and will be updated as further medical and scientific evidence becomes available.

Late referral of cancer patients with malnutrition to dietitians: a prospective study of clinical practice

PURPOSE

Malnutrition (MN) in cancer is common but underdiagnosed. Dietitian referrals may not occur until MN is established. We investigated cancer patient characteristics (demographics, nutritional status, and nutrition barriers) on referral to oncology dietitians. We also examined referral practices and prevalence of missed referral opportunities.

METHODS

This was a naturalistic multi-site study of clinical practice. Data from consecutive referrals were collected in inpatient and outpatient settings. Demographics, nutritional status (weight, body mass index (BMI), weight loss in the preceding 3-6 months, oral intake, nutrition barriers), referral reasons, and use of screening were recorded. Missed opportunities for earlier referral were also noted.

RESULTS

Two hundred patients were included (60% male, 51% inpatients). Half had gastrointestinal and hepatobiliary cancers. The majority were on antitumor treatment. Two-thirds had lost ≥ 5% body weight. Forty percent were overweight or obese. Seventy percent had ≥ 2 nutritional barriers. Most common nutrition barriers were anorexia, nausea, and early satiety. Greater weight loss and lower food intake were associated with ≥ 2 barriers. Weight loss was the most common referral reason. Screening was used in 35%. Referrals should have occurred sooner in nearly half (45%, n = 89).

CONCLUSIONS

Cancer patients were referred late to a dietitian, with multiple nutritional barriers. Most referrals were for established weight loss (WL). WL may be masked by pre-existing obesity. Almost half had missed earlier referral opportunities; screening was infrequent. Over one-quarter should have been re-referred sooner. There is a clear need for clinician education. Future research should investigate the optimal timing of dietitian referral and the best nutrition screening tools for use in cancer.

National survey of the management of Diabetic Ketoacidosis (DKA) in the UK in 2014

AIM

To examine, in a national survey, the outcomes of adult patients presenting with DKA in 2014, mapped against accepted UK national guidance.

METHODS

Data were collected in a standardized form covering clinical and biochemical outcomes, risk and discharge planning. The form was sent to all UK diabetes specialist teams (n = 220). Anonymized data were collected on five consecutive patients admitted with DKA between 1 May 2014 and 30 November 2014.

RESULTS

A total of 283 forms were received (n = 281 patients) from 72 hospitals, of which 71.4% used the national guidelines. The results showed that 7.8% of cases occurred in existing inpatients, 6.1% of admissions were newly diagnosed diabetes and 33.7% of patients had had at least one episode of DKA in the preceding year. The median times to starting 0.9% sodium chloride and intravenous insulin were 41.5 and 60 min, respectively. The median time to resolution was 18.7 h and the median length of hospital stay was 2.6 days. Significant adverse biochemical outcomes occurred, with 27.6% of patients developing hypoglycaemia and 55% reported as having hypokalaemia. There were also significant issues with care processes. Initial nurse-led observations were carried out well, but subsequent patient monitoring remained suboptimal. Most patients were not seen by a member of the diabetes specialist team during the first 6 h, but 95% were seen before discharge. A significant minority of discharge letters to primary care did not contain necessary information.

CONCLUSION

Despite widespread adoption of national guidance, several areas of management of DKA are suboptimal, being associated with avoidable biochemical and clinical risk.

Muckle-Wells syndrome without mutation in exon 3 of the NLRP3 gene, identified by evidence of excessive monocyte production of functional interleukin 1β and rapid response to anakinra

We report a man with lifelong urticaria, night sweats, arthralgia and lethargy. He had high levels of inflammatory markers and serum amyloid A, but no identifiable mutation in exon 3 of the NLRP3 (NOD-like receptor family, pyrin domain-1 containing 3) gene, and no relevant family history. We found marked production of functional interleukin (IL)-1 by the patient's monocytes at baseline and after stimulation with lipopolysaccharide. The patient made an immediate response to treatment with an IL-1β receptor antagonist. We propose that this patient has Muckle-Wells syndrome without deafness, occurring de novo. Functional screening for IL-1 production could aid diagnosis in future similar cases.

Paclitaxel disrupts polarized entry of membrane-permeable C6 ceramide into ovarian cancer cells resulting in synchronous induction of cell death

Exogenous cell-permeable C6 ceramide has been demonstrated to act synergistically with chemotherapeutic drugs, including paclitaxel, cisplatin, doxorubicin and the histone deacetylase inhibitor, trichostatin A, to induce cell death in a variety of cancer cells. We previously demonstrated that C6 ceramide and paclitaxel function synergistically to induce ovarian cancer cell death via modulation of the PI3/AKT cell survival pathway. In the present study, the entry pattern of C6 ceramide into ovarian cancer cells was investigated using fluorescent short chain C6-NBD sphingomyelin (C6-NBD). Confocal microscopy revealed that C6-NBD enters the cells in a polarized pattern, characterized by marked signals at one cellular end, representing a likely mitosis initiation site. Pretreatment of the cells with filipin, an inhibitor of the lipid raft/caveolae endocytosis pathway, decreases C6-NBD entry into the cells. A pretreatment with the water channel inhibitor, CuSO₄, was also found to reduce the entry of C6-NBD. Notably, the pretreatment with paclitaxel was shown to disrupt the polarized entry of C6-NBD into the cells, resulting in an even distribution of C6-NBD in the cytoplasm. In addition, the pretreatment of the cells with paclitaxel destabilized the cytoskeletal proteins, releasing an increased number of short tubulin fragments. The results of the present study indicate that C6 ceramide preferentially enters the cells via a predetermined initiation site of mitosis. In addition to diffusion, short chain C6 ceramide may also enter cells via water channels and caveolae-mediated endocytosis. Paclitaxel disrupts the cell cytoskeleton and induces an even distribution of C6 ceramide in the cytoplasm resulting in synergistic ovarian cancer cell death.

Abstract 5247: Human melanoma cells resist oxidative stress due to overactive MEK/ERK and AKT/mTOR pathways and overproduction of melanin

Melanoma is considered as one of the most aggressive and less treatable cancers. While various models of mechanisms have been proposed, the transformation from tranquil melanocytes to invasive melanoma cells remains an enigma. Alteration of cellular redox status has been suggested to be associated with cellular transformation. We compared primary human melanocytes and melanoma cells and their responses to oxidative stress. Both cells were treated with H2O2 at doses between 5 and 250μM. Microscopic data showed that melanoma cells are more resistant to H2O2 treatment. Western blot and confocal microscopic data showed that in melanoma cells, H2O2 does not induce CRT translocation which is considered as a mechanism through which melanocytes surrender to oxidative stress and induces immunogenic cell death. Furthermore, Western blot analysis showed that melanoma cells express EGFR, responsive to EGF treatment and have constitutive activation of AKT and mTOR, which are all related to better survival. In contrast, in the primary human melanocytes, EGFR expression is almost undetectable. And confocal microscopic data confirm this observation. Treatments of cells with MEK/ERK inhibitor U0126 and PI3K/AKT inhibitor LY294002 attenuates S6 phosphorylation. We also observed that in melanoma cells, but not in melanocytes, low dose (5 to 250μM) of H2O2 induces melanin production that is recognized to protect from further oxidative stress. Collectively, our data suggest that active MEK/ERK and AKT/mTOR pathways and up-regulation of melanin production contribute to the resistance of melanoma cells to oxidative stress and attribute to the aggressiveness of melanoma. Our data provides insights into the understanding of the molecular mechanisms of the transformation from melanocytes to melanoma and support the notion from the most recently published proteomic studies that EGFR remains one of the most important targets for better clinical management of melanoma.

Citation Format: David Calianese, Garrett Cammarata, Gabriella Brum, Kevin Szulak, Charles Best, Katelyn Higgins, Yinsheng Wan. Human melanoma cells resist oxidative stress due to overactive MEK/ERK and AKT/mTOR pathways and overproduction of melanin. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5247. doi:10.1158/1538-7445.AM2013-5247

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.

N-acetylcysteine potentiates doxorubicin-induced ATM and p53 activation in ovarian cancer cells

Doxorubicin has been used clinically to treat various types of cancer, and yet the molecular mode of actions of doxorubicin remains to be fully unraveled. In this study, we investigated the effect of doxorubicin on cultured ovarian cancer cells (CaOV3). MTT assay data showed that doxorubicin inhibits cell proliferation in a time- and dose-dependent manner. Phagokinetic cell motility assay data indicated that doxorubicin inhibits both basal level and EGF-induced cell migration in CaOV3 cells. Confocal microscopic data revealed that doxorubicin induces reorganization of cytoskeletal proteins including actin, tubulin and vimentin. Doxorubicin induces phosphorylation of p53 at Ser15 and 20, acetylation of p53 and ATM activation. Doxorubicin also induces phosphorylation of histone H2AX at Ser139. Interestingly, doxorubicin also inhibits mTOR activity, measured by phosphorylation of S6 ribosomal protein. Pretreatment of CaOV3 cells with antioxidant N-acetylcysteine (NAC), but not pyrrolidine dithiocarbamate (PDTC) potentiates doxorubicin-induced phosphorylation of p53 and ATM. Collectively, we conclude that doxorubicin induces ATM/p53 activation leading to reorganization of cytoskeletal networks, inhibition of mTOR activity, and inhibition of cell proliferation and migration. Our data also suggest that removal of oxidants by antioxidants such as NAC may enhance the efficacy of doxorubicin in vivo.

Abstract 3734: Paclitaxel disrupts polarized entry of membrane permeable C6 ceramide into ovarian cancer cells resulting in synchronous induction of cell death

Exogenous cell permeable C6 ceramide is demonstrated to act synergistically with chemotherapeutic drugs: paclitaxel, cisplatin, doxorubicin and histone deacetylase inhibitor trichostatin A (TSA) to induce cell death in a variety of cancer cells. We previously showed that C6 ceramide and paclitaxel act synergistically to induce ovarian cancer cell death via modulation of PI3/AKT cell survival pathway. This current study is focused on the process of C6 ceramide into the cell and its behavior during apoptosis. We investigated the entry pattern of C6 ceramide into ovarian cancer cells using fluorescent short chain C6-NBD sphingomyelin (or C6-NBD). As imaged with confocal microscopy, we observed that C6-NBD enters cells in a polarized pattern, characterized by strong signals at one cellular end, a probable mitosis initiation site. Pretreatment of the cells with filipin, an inhibitor of the raft/caveolae endocytosis pathway, decreases C6-NBD entry into cells. Pretreatment of water channel inhibitor CuSO4 also reduces entry of C6-NBD. Interestingly, pretreatment of cells with paclitaxel disrupts the polarized entry of C6-NBD into the cells, resulting in even distribution of C6-NBD in the cytoplasm. Further studies show that pretreatment of the cells with paclitaxel destabilizes cytoskeletal proteins, releasing increased number of short fragments of tubulins. The data suggests that C6 ceramide enters the cells preferably through a predetermined initial site of mitosis. In addition to diffusion, short chain C6 ceramide enters cells also via water channels and caveolae-mediated endocytosis. Paclitaxel disrupts cytoskeletons and induces an even distribution of C6 ceramide in the cytoplasm resulting in synergistic ovarian cancer cell death.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3734. doi:1538-7445.AM2012-3734