THUNDER 2: THeragnostic Utilities for Neoplastic DisEases of the Rectum by MRI guided radiotherapy

Background Neoadjuvant chemoradiation therapy (nCRT) is the standard treatment modality in locally advanced rectal cancer (LARC). Since response to radiotherapy (RT) is dose dependent in rectal cancer, dose escalation may lead to higher complete response rates. The possibility to predict patients who will achieve complete response (CR) is fundamental. Recently, an early tumour regression index (ERI) was introduced to predict pathological CR (pCR) after nCRT in LARC patients. The primary endpoints will be the increase of CR rate and the evaluation of feasibility of delta radiomics-based predictive MRI guided Radiotherapy (MRgRT) model. Methods Patients affected by LARC cT2-3, N0-2 or cT4 for anal sphincter involvement N0-2a, M0 without high risk features will be enrolled in the trial. Neoadjuvant CRT will be administered using MRgRT. The initial RT treatment will consist in delivering 55 Gy in 25 fractions on Gross Tumor Volume (GTV) plus the corresponding mesorectum and 45 Gy in 25 fractions on the drainage nodes. Chemotherapy with 5-fluoracil (5-FU) or oral capecitabine will be administered continuously. A 0.35 Tesla MRI will be acquired at simulation and every day during MRgRT. At fraction 10, ERI will be calculated: if ERI will be inferior than 13.1, the patient will continue the original treatment; if ERI will be higher than 13.1 the treatment plan will be reoptimized, intensifying the dose to the residual tumor at the 11th fraction to reach 60.1 Gy. At the end of nCRT instrumental examinations are to be performed in order to restage patients. In case of stable disease or progression, the patient will undergo surgery. In case of major or complete clinical response, conservative approaches may be chosen. Patients will be followed up to evaluate toxicity and quality of life. The number of cases to be enrolled will be 63: all the patients will be treated at Fondazione Policlinico Universitario A. Gemelli IRCCS in Rome. Discussion This clinical trial investigates the impact of RT dose escalation in poor responder LARC patients identified using ERI, with the aim of increasing the probability of CR and consequently an organ preservation benefit in this group of patients. Trial registration ClinicalTrials.gov Identifier: NCT04815694 (25/03/2021).

Primary Non-Hodgkin Uterine Lymphoma of the Cervix: A Literature Review

Introduction: Non-Hodgkin lymphomas (NHL) comprise 85% of the total lymphomas diagnosed, with the histological type of diffuse large B-cell lymphomas (DLBCL) being the most prevalent in adults. In about 40% of cases, the location is extranodal. Uterine cervix lymphomas of this type are extremely rare (0.5–1.5%) and represent a diagnostic challenge. A case of DLBCL of the cervix is presented here along with a review of the literature. Materials and methods: A 75-year-old patient was referred with a bleeding vegetant tumour occupying her entire vagina. The histological and pathological investigations performed following the tumour biopsy indicated a malignant, diffuse, vaguely nodular lymphoid tumour proliferation. The immunohistochemistry results were in favour of a diffuse B-cell non-Hodgkin lymphoma (DLBCL). CHOP (Cyclophosphamide, Hydroxydaunorubicin (also called doxorubicin or adriamycin), Oncovin (vincristine), Prednisone or Prednisolone) polychemotherapy and radiotherapy were effective and resulted in tumour regression (from 3.4 cm to tumour disappearance, with the cervix returning to normal size). Conclusions: The uterine cervix lymphoma prognosis is more conservative than that for a nodal lymphoma, mainly due to a later diagnosis determined via immunohistochemistry. Chemotherapy is the main treatment.

Long-term non-invasive drug treatments for adult zebrafish

Zebrafish embryos are widely used for drug-discovery however administering drugs to adult zebrafish is limited by current protocols that can cause stress. Here, we develop a drug formulation and administration method for adult zebrafish by producing food-based drug pellets which are consumed voluntarily. We apply this to zebrafish with BRAF-mutant melanoma, a model that has significantly advanced our understanding of melanoma progression, but not of drug resistance due to the limitations of current treatment methods. Short-term, precise, and daily dosing with drug-pellets made with the BRAFV600E inhibitor, vemurafenib, led to tumour regression. On-target drug efficacy was determined by phospho-ERK staining. Continued drug treatment led to the emergence, for the first time in zebrafish, of acquired drug resistance and melanoma relapse, modelling the responses seen in melanoma patients. This method presents a controlled, non-invasive approach that permits long-term drug studies, and can be widely applied to any adult zebrafish model.

Development of a Hypoxia-Activated Trehalose Diester for the Treatment of Solid Tumours

<p><b>The potential of bacterial cell wall components in the treatment of various cancers was initially realised in the late 1800s during pioneering work with Coley’s toxins. Since this preliminary work, efforts have been concentrated on the isolation and identification of bacterial components that lead to tumour regression. Trehalose dimycolates (TDMs) are compounds isolated from the M. tuberculosis cell wall and are known to activate macrophages to give a polarised Th1 immune response resulting in reduced tumour burden. Consequently, TDMs have shown great promise in the treatment of solid tumours.</b></p> <p>In this thesis, work is presented towards the synthesis of trehalose glycolipid prodrugs that will be specifically activated inside the hypoxic tumour microenvironment, and thereby lead to a more selective form of cancer therapy. These hypoxia-activated trehalose glycolipids incorporate a nitroimidazole trigger that fragments upon enzymatic reduction (in the absence of oxygen) to give the active glycolipid. Throughout the course of this work, it was determined that the nitroimidazole trigger group could not be directly attached to the glycolipid and thus, an alternative carbonate-linker strategy was explored through the use of a reporter fluoroprobe. The validity of this approach was determined in various enzyme and cell-based assays.</p>

Development of a Hypoxia-Activated Trehalose Diester for the Treatment of Solid Tumours

<p><b>The potential of bacterial cell wall components in the treatment of various cancers was initially realised in the late 1800s during pioneering work with Coley’s toxins. Since this preliminary work, efforts have been concentrated on the isolation and identification of bacterial components that lead to tumour regression. Trehalose dimycolates (TDMs) are compounds isolated from the M. tuberculosis cell wall and are known to activate macrophages to give a polarised Th1 immune response resulting in reduced tumour burden. Consequently, TDMs have shown great promise in the treatment of solid tumours.</b></p> <p>In this thesis, work is presented towards the synthesis of trehalose glycolipid prodrugs that will be specifically activated inside the hypoxic tumour microenvironment, and thereby lead to a more selective form of cancer therapy. These hypoxia-activated trehalose glycolipids incorporate a nitroimidazole trigger that fragments upon enzymatic reduction (in the absence of oxygen) to give the active glycolipid. Throughout the course of this work, it was determined that the nitroimidazole trigger group could not be directly attached to the glycolipid and thus, an alternative carbonate-linker strategy was explored through the use of a reporter fluoroprobe. The validity of this approach was determined in various enzyme and cell-based assays.</p>

P-OGC24 Comparison of the histopathological regression after neoadjuvant FLOT versus ECX in resectable gastroesophageal adenocarcinoma

Background Neoadjuvant chemotherapy is a key component in the treatment of resectable oesophagogastric cancer (OGC). Histopathological tumour regression is associated with a prognostic benefit in OGC. There is increased usage of the FLOT regimen as part of neoadjuvant chemotherapy (NAC) for these tumours. The initial phase 2 trial demonstrated complete pathological response (pCR) in 15% for FLOT versus 6% for ECX but there is no data outside a trial setting. The aim of this study was to evaluate the differences in pCR and the extent of downstaging between patients receiving FLOT versus ECX in the neoadjuvant setting. Methods Consecutive patients treated for OGC in a single, high-volume UK centre between 2018 and 2021 were identified from a contemporaneously maintained database. Patients underwent 3 cycles of ECX or 4 cycles of FLOT as part of NAC. Histopathological tumour regression was assessed by the Mandard classification. A comparison of T- and N stage migration between FLOT and ECX was performed. Major pCR was defined as TRG 1-2 based on the Mandard classification. Results The study included 162 patients. 6/84 (7.1%) patients receiving ECX and 5/78 (6.4%) patients receiving FLOT achieved a pCR (p = 0.853). 11/84 (13.1%) patients in the ECX group and 12/78 (15.4%) patients in the FLOT group achieved a major pCR (p = 0.677). With regards to stage migration by T-stage, 36 (42.9%) patients were downstaged and 6 patients (7.1%) were upstaged with ECX. Amongst FLOT patients, 42 (53.8%) were downstaged and 8 (10.3%) upstaged (p = 0.189). When comparing N-stage, 29 (34.5%) patients achieved downstaging and 28 (33.3%) were upstaged with ECX. 30 (38.5%) patients were downstaged and 20 (25.6%) were upstaged with FLOT (0.563). Conclusions There was no significant difference in pCR and stage migration rates between patients receiving neoadjuvant ECX and FLOT. pCR rates were lower than previously reported, and it is unclear if the difference in prognosis will translate comparable outcomes between patients receiving ECX versus FLOT.

O-OGC06 Genomic analysis of response to neoadjuvant chemotherapy in oesophageal adenocarcinoma

Background Oesophageal adenocarcinoma (OAC) is the ninth most common cancer worldwide, with an estimated mortality of over 500,000 deaths yearly. Neoadjuvant chemotherapy (NAC) followed by surgery is the standard of care (SOC) for locally advanced OAC. Although almost all patients receive chemotherapy as SOC, fewer than 20% obtain a clinically meaningful response and benefit before surgery. The OAC genome is complex and heterogeneous between patients, and it is not yet understood whether specific mutational patterns may result in chemotherapy sensitivity or resistance. Methods To identify associations between genomic events and response to NAC in OAC, a comparative genomic analysis was performed in 65 patients using whole-genome sequencing. We defined response to NAC using Mandard Tumour Regression Grade (TRG), with responders classified as TRG1-2 (n = 27) and non-responders classified as TRG4-5 (n = 38). Results We report a higher non-synonymous mutation burden in responders (median 2.08/Mb vs 1.70/Mb, P = 0.036) and elevated copy number variation (CNV) in non-responders (282 vs 136/patient, P&lt;0.001). We identified CNVs unique to each group, with cell cycle (CDKN2A, CCND1), c-Myc (MYC), RTK/PIK3 (KRAS, EGFR) and gastrointestinal differentiation (GATA6) pathway genes being specifically altered in non-responders. Of particular interest was the identification of the Neuron Navigator-3 (NAV3), a known tumour suppressor downstream of EGFR, which was mutated exclusively in non-responders with a frequency of 22%. Conclusions Our work characterises genetic features and mutations that are uniquely associated with response to NAC. We envision a treatment pipeline that incorporates driver mutation profiling in OAC, combining response prediction with targeted therapies to enhance response to NAC and improve survival outcomes.

P-OGC29 Pathological response profiles of FLOT and ECX neoadjuvant chemotherapy in oesophageal adenocarcinoma

Background 70% of patients undergoing neo-adjuvant ECX chemotherapy for adenocarcinoma of the oesophagus, show little to know response in their primary tumour (Mandard 4,5). However, among these patients, those who have a complete nodal response (cN+ to ypN0) have equivalent survival to those with Mandard 1,2,3 tumours. FLOT chemotherapy has shown a survival advantage to ECX, however, rates of primary tumour response and nodal response are yet to be the focus of published study. Methods Retrospective cohort study comparing patients undergoing ECX and FLOT neoadjuvant chemotherapy between 2014 and 2021. Pathological outcomes were examined including, Mandard tumour regression grade (1-5), complete nodal response (cN+ to ypN0), clinically node negative nodal progression (cN0 to ypN+). Results 226 patients had data available for analysis (193 ECX and 33 FLOT). 27% (52/193) of patients receiving ECX showed a response in the primary tumour (Mandard 1,2,3) compared to 63% (21/33) with patients undergoing FLOT (p &lt; 0.001). Complete nodal response rates were 25% in ECX patients and 21% FLOT patients (p = 0.556). Clinically node negative nodal upstaging (cN0 to pN+) was higher among FLOT patients 30% (13/33) than ECX patients 12% (24/193) (p &lt; 0.001). Conclusions FLOT chemotherapy confers improved primary tumour response. However, these findings were not echoed in locoregional nodal responses. Survival advantages with FLOT may result from improved responses in primary tumour and not improved systemic coverage. More data will be needed to explore this and over-come the confounding effect of staging inaccuracies. However, understanding systemic and loco-regional responses of different chemotherapy regimens will be needed to tailor future neoadjuvant treatment regimens.

Histopathology-guided management of ocular surface squamous neoplasia with corneal stromal or scleral invasion using ruthenium-106 plaque brachytherapy

Background/aimTo evaluate the safety and efficacy of ruthenium-106 (Ru-106) plaque brachytherapy in managing invasive ocular surface squamous neoplasia (OSSN).MethodsThis is a retrospective, non-comparative, interventional case series of 42 eyes with OSSN with histopathologically-proven corneal stromal and/or scleral invasion that underwent Ru-106 plaque brachytherapy. Main outcome measures were tumour regression, eye salvage, final visual acuity, treatment complications and metastasis.ResultsAt presentation, the mean tumour basal diameter was 9.3 mm (range 5–26 mm) and thickness 3.1 mm (range 1.5–11 mm). Prior treatment included excision biopsy in two patients (5%), incision biopsy and topical interferon in one each (2%). Following excision with 4 mm clinically clear margins, corneal stromal and/or scleral invasion of OSSN was confirmed in all 42 cases, with the excised base showing invasive squamous cell carcinoma. A total dose of 5000 cGy over a mean duration of 19.7 hours (range 7–41 hours) was provided to an axial depth of 2 mm using Ru-106 surface plaque. Over a mean follow-up of 36.9 months (range 22.3–72 months), complete tumour regression was achieved in all eyes (100%). Two eyes (5%) showed conjunctival tumour growth remote from the site of prior treatment. Visual acuity was maintained at ≥20/200 in 35 eyes (83%), with a loss of >2 Snellen lines in 1 eye (2%). There was no evidence of regional lymph node or systemic metastasis.ConclusionHistopathology-guided use of Ru-106 surface plaque brachytherapy is a safe and an effective adjuvant therapy in the management of corneal stromal and/or scleral invasion of OSSN.