Biology-guided radiotherapy in metastatic prostate cancer: time to push the envelope?

The therapeutic landscape of metastatic prostate cancer has undergone a profound revolution in recent years. In addition to the introduction of novel molecules in the clinics, the field has witnessed a tremendous development of functional imaging modalities adding new biological insights which can ultimately inform tailored treatment strategies, including local therapies. The evolution and rise of Stereotactic Body Radiotherapy (SBRT) have been particularly notable in patients with oligometastatic disease, where it has been demonstrated to be a safe and effective treatment strategy yielding favorable results in terms of disease control and improved oncological outcomes. The possibility of debulking all sites of disease, matched with the ambition of potentially extending this treatment paradigm to polymetastatic patients in the not-too-distant future, makes Biology-guided Radiotherapy (BgRT) an attractive paradigm which can be used in conjunction with systemic therapy in the management of patients with metastatic prostate cancer.

Image-guided moderately hypofractionated radiotherapy for localized prostate cancer: a multicentric retrospective study (IPOPROMISE).

BACKGROUND: Moderate hypofractionated radiotherapy is a treatment option for the cure of localized prostate cancer (PCa) patients based on the results of randomized prospective trials, but there is a clinical concern about the relatively short length of follow-up, and real-world results on outcome and toxicity based on cutting-edge techniques are lacking. The objective of this study is to present the long-term results of a large multicentric series. MATERIALS AND METHODS: We retrospectively evaluated 1325 PCa patients treated with daily volumetric image-guided hypofractionated radiotherapy between 2007 and 2020 in 16 Centers. For survival endpoints, we used Kaplan-Meier survival curves and fitted univariate and multivariable Cox's proportional hazards regression models to study the association between the clinical variables and each survival type. RESULTS: At the end of the follow-up, 11 patients died from PCa. The 15-year values of cancer-specific survival (CSS) and biochemical relapse-free survival (b-RFS) were 98.5% (95%CI 97.3-99.6%) and 85.5% (95%CI 81.9-89.4%), respectively. The multivariate analysis showed that baseline PSA, Gleason score, and the use of androgen deprivation therapy were significant variables for all the outcomes. Acute gastrointestinal (GI) and genitourinary (GU) toxicities of grade ≥ 2 were 7.0% and 16.98%, respectively. The 15-year late grade ≥ 2 GI and GU toxicities were 5% (95%CI 4-6%) and 6% (95%CI 4-8%), respectively. CONCLUSION: Real-world long-term results of this multicentric study on cutting-edge techniques for the cure of localized PCa demonstrated an excellent biochemical-free survival rate of 85.5% at 15 years, and very low rates of ≥ G3 late GU and GI toxicity (1.6% and 0.9% respectively), strengthening the results of the available published trials.

High dose proton and photon-based radiation therapy for 213 liver lesions: a multi-institutional dosimetric comparison with a clinical perspective.

BACKGROUND: Stereotactic radiotherapy (SRT) and Proton therapy (PT) are both options in the management of liver lesions. Limited clinical-dosimetric comparison are available. Moreover, dose-constraint routinely used in liver PT and SRT considers only the liver spared, while optimization strategies to limit the liver damaged are poorly reported. METHODS: Primary endpoint was to assess and compare liver sparing of four contemporary RT techniques. Secondary endpoints were freedom from local recurrence (FFLR), overall survival (OS), acute and late toxicity. We hypothesize that Focal Liver Reaction (FLR) is determined by a similar biologic dose. FLR was delineated on follow-up MRI. Mean C.I. was computed for all the schedules used. A so-called Fall-off Volume (FOV) was defined as the area of healthy liver (liver-PTV) receiving more than the isotoxic dose. Fall-off Volume Ratio (FOVR) was defined as ratio between FOV and PTV. RESULTS: 213 lesions were identified. Mean best fitting isodose (isotoxic doses) for FLR were 18Gy, 21.5 Gy and 28.5 Gy for 3, 5 and 15 fractions. Among photons, an advantage in terms of healthy liver sparing was found for Vmat FFF with 5mm jaws (p = 0.013) and Cyberknife (p = 0.03). FOV and FOVR resulted lower for PT (p < 0.001). Three years FFLR resulted 83%. Classic Radiation induced liver disease (RILD, any grade) affected 2 patients. CONCLUSIONS: Cyberknife and V-MAT FFF with 5mm jaws spare more liver than V-MAT FF with 10 mm jaws. PT spare more liver compared to photons. FOV and FOVR allows a quantitative analysis of healthy tissue sparing performance showing also the quality of plan in terms of dose fall-off.

Modulation of tumor-associated macrophage activity with radiation therapy: a systematic review.

OBJECTIVE: Tumor-associated macrophages (TAMs) are the most represented cells of the immune system in the tumor microenvironment (TME). Besides its effects on cancer cells, radiation therapy (RT) can alter TME composition. With this systematic review, we provide a better understanding on how RT can regulate macrophage characterization, namely the M1 antitumor and the M2 protumor polarization, with the aim of describing new effective RT models and exploration of the possibility of integrating radiation with other available therapies. METHODS: A systematic search in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was carried out in PubMed, Google Scholar, and Scopus. Articles from January 2000 to April 2020 which focus on the role of M1 and M2 macrophages in the response to RT were identified. RESULTS: Of the 304 selected articles, 29 qualitative summary papers were included in our analysis (16 focusing on administration of RT and concomitant systemic molecules, and 13 reporting on RT alone). Based on dose intensity, irradiation was classified into low (low-dose irradiation, LDI; corresponding to less than 1 Gy), moderate (moderate-dose irradiation, MDI; between 1 and 10 Gy), and high (high-dose irradiation, HDI; greater than 10 Gy). While HDI seems to be responsible for induced angiogenesis and accelerated tumor growth through early M2-polarized TAM infiltration, MDI stimulates phagocytosis and local LDI may represent a valid treatment option for possible combination with cancer immunotherapeutic agents. CONCLUSION: TAMs seem to have an ambivalent role on the efficacy of cancer treatment. Radiation therapy, which exerts its main antitumor activity via cell killing, can in turn interfere with TAM characterization through different modalities. The plasticity of TAMs makes them an attractive target for anticancer therapies and more research should be conducted to explore this potential therapeutic strategy.

Recommendations for radiation therapy in oligometastatic prostate cancer: An ESTRO-ACROP Delphi consensus.

BACKGROUND AND PURPOSE: Oligometastatic prostate cancer is a new and emerging treatment field with only few prospective randomized studies published so far. Despite the lack of strong level I evidence, metastasis-directed therapies (MDT) are widely used in clinical practice, mainly based on retrospective and small phase 2 studies and with a large difference across centers. Pending results of ongoing prospective randomized trials, there is a clear need for more consistent treatment indications and radiotherapy practices. MATERIAL AND METHODS: A European Society for Radiotherapy and Oncology (ESTRO) Guidelines Committee consisting of radiation oncologists' experts in prostate cancer was asked to answer a dedicated questionnaire, including 41 questions on the main controversial issues with regard to oligometastatic prostate cancer. RESULTS: The panel achieved consensus on patient selection and routine use of prostate-specific membrane antigen positron emission tomography (PSMA PET) imaging as preferred staging and restaging imaging. MDT strategies are recommended in the de novo oligometastatic, oligorecurrent and oligoprogressive disease setting for nodal, bone and visceral metastases. Radiation therapy doses, volumes and techniques were discussed and commented. CONCLUSION: These recommendations have the purpose of providing standardization and consensus to optimize the radiotherapy treatment of oligometastatic prostate cancer until mature results of randomized trials are available.

A systematic review and meta-analysis on non-metastatic castration resistant prostate cancer: The radiation oncologist's perspective.

Prostate cancer is the second most common cause of cancer-related mortality in men. In patients undergoing a failure after radical treatment, one of the therapeutic option is androgen deprivation: despite initial response rates, a progression to a state of castration resistance is observed in most of the patients. In the present article, we conducted a systematic review and meta-analysis of all clinical trials assessing treatment for nmCRPC with next-generation androgen receptor inhibitors. We performed a review and meta-analysis of phase III randomized controlled trials comparing new agents (apalutamide, enzalutamide, darolutamide) with placebo as control arm, in the setting of nmCRPC. Patients treated with next-generation ARIs had a 26% reduction in the risk of death compared with placebo; compared with other ARIs, darolutamide had the lowest rate of grade 3 and 4 AEs and the lowest therapy discontinuation rate due to any grade AEs. This meta-analysis shows that treatment with new ARIs is safe and significantly reduces the risk of death and of metastasis onset in nmCRPC patients. Under way studies on new biomarkers such as genomic classifiers will probably allow the stratification in more specific subsets of disease. New imaging modalities such as PSMA-PET have shown greater sensibility and specificity than conventional imaging in metastases detection. All patients were randomized in a 2:1 fashion, with a total of 2,694 who underwent next-generation ARIs (806 apalutamide, 955 darolutamide, 933 enzalutamide) and 1,423 in the placebo arm.

The oncogenic landscape of the idiopathic pulmonary fibrosis: a narrative review.

Background and Objective: Translational research is a source of continuous innovation in medicine, more particularly for clinical research on new treatment modalities in idiopathic pulmonary fibrosis (IPF) patients. However, the heterogeneity of the disease is well recognized, and different pathological and molecular settings have been identified. The molecular mechanisms by which IPF proceeds in time and space remains poorly understood. Although some IPF features are reminiscent of cancer, the dynamics of malignant divergent clonal selective pressure and heterogeneity clearly differ from those occurring in IPF. This is reflected in the absence of patient proper selection and stratification to biological agents (pirfenidone, nintedanib) which limit therapeutic efficacy. Consequently, increased costs are related to the clinical management of advanced IPF patients. Steady collaboration and fluid communication between pneumo-oncologists, radiologists and molecular biologists is a clear priority for the correct interpretation of tests and the definition of effective personalized strategies against this orphan disease. The present work aims at providing the most relevant hints shared by cancer and IPF. Methods: A systematic literature review was performed to identify all relevant data. The examined databases were Scopus, Web of Science, Cochrane, Google Scholar, and PubMed. The last search was run on January 5, 2022. We have primarily conducted separated research for lung cancer, IPF, genetics, epigenetics, surgery in IPF and cancer. Key Content and Findings: The data here presented mainly focus on gene mutations, epigenetics and novel therapeutic approaches. Moreover, epidemiology, prognostic variables and in new treatment strategies adopted in patients with IPF and lung cancer are discussed as well. Conclusions: Overall, the findings of this narrative review will be of help in defining the key molecular features that could applied in IPF setting with promising rationale to improve therapy and to better manage those cases carrying IPF and cancer concomitantly.

Preliminary report on harmonization of features extraction process using the ComBat tool in the multi-center "Blue Sky Radiomics" study on stage III unresectable NSCLC.

BACKGROUND AND PURPOSE: In the retrospective-prospective multi-center "Blue Sky Radiomics" study (NCT04364776), we plan to test a pre-defined radiomic signature in a series of stage III unresectable NSCLC patients undergoing chemoradiotherapy and maintenance immunotherapy. As a necessary preliminary step, we explore the influence of different image-acquisition parameters on radiomic features' reproducibility and apply methods for harmonization. MATERIAL AND METHODS: We identified the primary lung tumor on two computed tomography (CT) series for each patient, acquired before and after chemoradiation with i.v. contrast medium and with different scanners. Tumor segmentation was performed by two oncological imaging specialists (thoracic radiologist and radio-oncologist) using the Oncentra Masterplan® software. We extracted 42 radiomic features from the specific ROIs (LIFEx). To assess the impact of different acquisition parameters on features extraction, we used the Combat tool with nonparametric adjustment and the longitudinal version (LongComBat). RESULTS: We defined 14 CT acquisition protocols for the harmonization process. Before harmonization, 76% of the features were significantly influenced by these protocols. After, all extracted features resulted in being independent of the acquisition parameters. In contrast, 5% of the LongComBat harmonized features still depended on acquisition protocols. CONCLUSIONS: We reduced the impact of different CT acquisition protocols on radiomic features extraction in a group of patients enrolled in a radiomic study on stage III NSCLC. The harmonization process appears essential for the quality of radiomic data and for their reproducibility. ClinicalTrials.gov Identifier: NCT04364776, First Posted:April 28, 2020, Actual Study Start Date: April 15, 2020, https://clinicaltrials.gov/ct2/show/NCT04364776 .

Radiotherapy at oligoprogression for metastatic castration-resistant prostate cancer patients: a multi-institutional analysis.

PURPOSE: To retrospectively estimate the impact of radiotherapy as a progression-directed therapy (PDT) in oligoprogressive metastatic castration-resistant prostate cancer (mCRPC) patients under androgen receptor-target therapy (ARTT). MATERIALS AND METHODS: mCRPC patients are treated with PDT. End-points were time to next-line systemic treatment (NEST), radiological progression-free survival (r-PFS) and overall survival (OS). Toxicity was registered according to Common Terminology Criteria for Adverse Events v4.0. Survival analysis was performed using the Kaplan-Meier method; univariate and multivariate analyses were performed. RESULTS: Fifty-seven patients were analyzed. The median follow-up after PDT was 25.2 months (interquartile, 17.1-44.5). One-year NEST-free survival, r-PFS and OS were 49.8%, 50.4% and 82.1%, respectively. At multivariate analysis, polymetastatic condition at diagnosis of metastatic hormone-sensitive prostate cancer (mHSPC) (HR 2.82, p = 0.004) and PSA doubling time at diagnosis of mCRPC (HR 2.76, p = 0.006) were associated with NEST-free survival. The same variables were associated with r-PFS (HR 2.32, p = 0.021; HR 2.24, p = 0.021). One patient developed late grade ≥ 2 toxicity. CONCLUSION: Our study shows that radiotherapy in oligoprogressive mCRPC is safe, is effective and seems to prolong the efficacy of ARTT in patients who otherwise would have gone systemic treatment switch, positively affecting disease progression. Prospective trials are needed.

Stereotactic prostate radiotherapy with or without androgen deprivation therapy, study protocol for a phase III, multi-institutional randomized-controlled trial.

Objective: The therapeutic landscape for localized prostate cancer (PC) is evolving. Stereotactic radiotherapy (SRT) has been reported to be at least not inferior to standard radiotherapy, but the effect of androgen deprivation therapy (ADT) in this setting is still unknown and its use is left to clinical judgment. There is therefore the need to clarify the role of ADT in association with SRT, which is the aim of the present study. Methods: We present a study protocol for a randomized, multi-institutional, Phase III clinical trial, designed to study SRT in unfavorable intermediate and a subclass of high-risk localized PC. Patients (pts) will be randomized 1:1 to SRT + ADT or SRT alone. SRT will consists in 36.25 Gy in 5 fractions, ADT will be a single administration of Triptorelin 22.5 mg concurrent to SRT. Primary end point will be biochemical disease-free survival. Secondary end points will be disease-free survival, freedom from local recurrence, freedom from regional recurrence, freedom from distant metastasis and overall survival (OS); quality of life QoL and patient reported outcomes will be an exploratory end point and will be scored with EPIC-26, EORTC PR 25, IPSS, IIEF questionnaires in SRT + ADT and SRT alone arms. Moreover, clinician reported acute and late toxicity, assessed with CTCAE v. 5.0 scales will be safety end points. Results: Sample size is estimated of 310 pts. For acute toxicity and quality of life results are awaited after 6 months since last patient in, whereas, for efficacy end points and late toxicity mature results will be available 3-5 years after last patient in. Conclusion: Evidence is insufficient to guide decision making concerning ADT administration in the new scenario of prostate ultra-hypofractionation. Hence, the need to investigate the ADT role in SRT specific setting. Advances in knowledge: The stereotactic prostate radiotherapy with or without ADT trial (SPA Trial) has been designed to establish a new standard of care for SRT in localized unfavorable intermediate and a subclass of localized high risk PC.

Local Therapies and Modulation of Tumor Surrounding Stroma in Malignant Pleural Mesothelioma: A Translational Approach.

Malignant Pleural Mesothelioma (MPM) is a rare and aggressive neoplasm of the pleural mesothelium, mainly associated with asbestos exposure and still lacking effective therapies. Modern targeted biological strategies that have revolutionized the therapy of other solid tumors have not had success so far in the MPM. Combination immunotherapy might achieve better results over chemotherapy alone, but there is still a need for more effective therapeutic approaches. Based on the peculiar disease features of MPM, several strategies for local therapeutic delivery have been developed over the past years. The common rationale of these approaches is: (i) to reduce the risk of drug inactivation before reaching the target tumor cells; (ii) to increase the concentration of active drugs in the tumor micro-environment and their bioavailability; (iii) to reduce toxic effects on normal, non-transformed cells, because of much lower drug doses than those used for systemic chemotherapy. The complex interactions between drugs and the local immune-inflammatory micro-environment modulate the subsequent clinical response. In this perspective, the main interest is currently addressed to the development of local drug delivery platforms, both cell therapy and engineered nanotools. We here propose a review aimed at deep investigation of the biologic effects of the current local therapies for MPM, including cell therapies, and the mechanisms of interaction with the tumor micro-environment.

Integrating data from multidisciplinary Management of Malignant Pleural Mesothelioma: a cohort study.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare and aggressive malignancy that most commonly affects the pleural layers. MPM has a strong association with asbestos, mainly caused by exposure to its biopersistent fibers in at least 80% of cases. Individuals with a chronic exposure to asbestos might develop disease with a 20-40-year latency with few or no symptoms. Such has been the case in the Italian regions of Piedmont and Lombardy, where industrial production of materials laden with asbestos, mainly cements, has been responsible for the onset of a large epidemic. Since 2018, a multidisciplinary team at San Matteo hospital in Pavia has been collecting data on over 100 patients with MPM. The main goal of this project is to define and describe an integrated profile for each MPM case at diagnosis by using data mining and partition analysis. METHODS: Here we bring together exhaustive epidemiologic, histologic and radiologic data of 88 MPM patients that came to our observation and draw correlations with predictive and prognostic significance. RESULTS: The median overall survival (OS) was 15.6 months. Most patients presented with pleural effusion, irrespective of disease stage. Quite unexpectedly, no statistically significant association was demonstrated between OS and TNM disease stage at diagnosis. Although average OS is similar in male and female patients, partition analysis of data underlined a significant differential hierarchy of predictor categories based on patient gender. In females with no smoking history, full chemotherapeutic regimens are associated with better outcomes. Moreover, concerning second line treatments, vinorelbine emerged as the most advantageous choice for female patients, whereas in the male subgroup no statistically significant difference resulted between gemcitabine and vinorelbine. CONCLUSION: A multidisciplinary approach to MPM is mandatory to define better therapeutic approaches, personalize the management and improve patient outcomes.

Upfront metastasis-directed therapy in oligorecurrent prostate cancer does not decrease the time from initiation of androgen deprivation therapy to castration resistance.

The aim of the present study was to explore the potential impact of upfront metastases-directed therapy (MDT) in terms of prolongation of castration-sensitive phase in a series of oligorecurrent castration-sensitive prostate cancer (PC) patients. The present article is a multicenter retrospective study. The population of interest was castrate-sensitive oligorecurrent PC, defined as the presence of 1-3 uptakes in non-visceral sites such as bones or nodes detected by means of 18F-Choline PET/CT or 68-Gallium PSMA PET/CT. Primary endpoint was the time to castration resistance. Secondary endpoints were ADT-free survival, local progression-free survival, and overall survival. Eighty-two patients and 118 lesions were analyzed. The median time to castration resistance for the entire population of the study was 49 months (95% CI 43.6-54.4 months). The 1- and 2-year TTCR-free survival rates were 94% and 82%, respectively. At the time of analysis, 52 patients were still in the castration-sensitive phase of the disease. In this cohort of patients, the median ADT-free survival was 20 months (range 3-69 months). On the other hand, during follow-up 30 patients switched to the castration-resistant phase of disease. In this last group of patients, the median ADT-free survival was 20 months (range 4-50 months). After the ADT administration, the median castration-sensitive phase was 29 months (range 5-71 months). Castration resistance generally occurs at a median follow-up of 24-36 months following ADT. In the current study, upfront MDT does not decrease the time from initiation of ADT to castration resistance.

The Evolving Landscape of the Molecular Epidemiology of Malignant Pleural Mesothelioma.

Malignant pleural mesothelioma (MPM) is a rare and aggressive malignancy that most commonly affects the pleural lining of the lungs. It has a strong association with exposure to biopersistent fibers, mainly asbestos (80% of cases) and-in specific geographic regions-erionite, zeolites, ophiolites, and fluoro-edenite. Individuals with a chronic exposure to asbestos generally have a long latency with no or few symptoms. Then, when patients do become symptomatic, they present with advanced disease and a worse overall survival (about 13/15 months). The fibers from industrial production not only pose a substantial risk to workers, but also to their relatives and to the surrounding community. Modern targeted therapies that have shown benefit in other human tumors have thus far failed in MPM. Overall, MPM has been listed as orphan disease by the European Union. However, molecular high-throughput profiling is currently unveiling novel biomarkers and actionable targets. We here discuss the natural evolution, mainly focusing on the novel concept of molecular epidemiology. The application of innovative endpoints, quantification of genetic damages, and definition of genetic susceptibility are reviewed, with the ultimate goal to point out new tools for screening of exposed subject and for designing more efficient diagnostic and therapeutic strategies.

Immune Stroma in Lung Cancer and Idiopathic Pulmonary Fibrosis: A Common Biologic Landscape?

Idiopathic pulmonary fibrosis (IPF) identifies a specific entity characterized by chronic, progressive fibrosing interstitial pneumonia of unknown cause, still lacking effective therapies. Growing evidence suggests that the biologic processes occurring in IPF recall those which orchestrate cancer onset and progression and these findings have already been exploited for therapeutic purposes. Notably, the incidence of lung cancer in patients already affected by IPF is significantly higher than expected. Recent advances in the knowledge of the cancer immune microenvironment have allowed a paradigm shift in cancer therapy. From this perspective, recent experimental reports suggest a rationale for immune checkpoint inhibition in IPF. Here, we recapitulate the most recent knowledge on lung cancer immune stroma and how it can be translated into the IPF context, with both diagnostic and therapeutic implications.

OLIGO-AIRO: a national survey on the role of radiation oncologist in the management of OLIGO-metastatic patients on the behalf of AIRO.

In the last years, several evidences demonstrated the role of stereotactic body radiotherapy (SBRT) in the oligometastatic disease and the possibility to increase survival in selected patients. In 2020 the study group "biology and treatment of the oligometastatic disease" of the Italian Association of Radiotherapy and Clinical Oncology (AIRO) conducted a survey evaluating the attitude of physicians in treating the oligometastatic disease and the definition of it. An electronic questionnaire was administered online to the society members. 105 questionnaires were returned. 78% responders considered as oligometastatic a disease with ≤ 5 metastases. The majority of the responders (77%) treated > 50 patients in the last year, and 89% responders agreed in considering every oligometastatic tumor susceptible to local treatments. Regarding the clinical management of the oligometastatic disease, the majority of the responders (66%) suggested an interdisciplinary discussion. When choosing a treatment option for fit patients with a single oligometastatic focus, 52% of the responders agreed in proposing only SBRT. In the case of unfit patients with a single oligometastatic lesion the agreement was in favor of the SBRT alone (89%). In the oligoprogressive setting, 41% responders opted to continue the current systemic treatment and to add SBRT, while in the case of oligoresidual disease, 70% responders was in favor of adding SBRT and continuing the current systemic treatment. In conclusions, the survey illustrated the current agreement and prescribing attitude for oligometastatic patients in Italy. The non-homogenous agreement in some clinical scenarios suggest the need of more robust evidence.

Stereotactic body radiotherapy (SBRT) in combination with drugs in metastatic kidney cancer: A systematic review.

OBJECTIVE: To conduct a systematic review and meta-analysis of the role of SBRTdrug combination in patients affected by mRCC and associated oncologic outcomes and toxicity profiles. EVIDENCE ACQUISITION: We performed a critical review of the Pubmed, Medline, and Embase databases from January 1, 2000 through April 30, 2020 according to the Preferred Reporting Items and Meta-Analyses statement. To assess the overall quality of the literature reviewed, we used a modified Delphi tool. EVIDENCE SYNTHESIS: A total of 6 studies were included, corresponding to a cohort of 216 patients. Tyrosine Kinases Inhibitors were the most widely used drugs in combination with SBRT, being administered in 93% patients. No study reported an increase of radiation-induced toxicity. CONCLUSIONS: SBRT resulted to be safe, without increase in terms of drugs-related adverse events in this setting. Moreover, this approach showed promising clinical outcomes in terms of LC and OS.