Photodynamic therapy (PDT) utilizes a sensitizer agent and light to produce selective cell death. Dermatologists are familiar with PDT for the treatment of actinic keratoses and early nonmelanoma skin cancers, and recent studies have elucidated that PDT has resulted in improved morbidity and secondary outcomes for the treatment of various cancerous and precancerous solid tumors. Light source and dosimetry may be modified to selectively target tissue, and novel techniques such as fractionation, metronomic pulsation, continuous light delivery, and chemophototherapy are under investigation for further optimization of therapy. This article aims to review the expanding indications for PDT and demonstrate the potential of this modality to decrease morbidity and increase quality of life for patients. To illustrate these new indications, we provide a focused review of the latest literature on PDT for dermatologic and other solid tumors including gastrointestinal, peritoneal, lung, genitourinary, brain, breast, and head and neck. Data on efficacy, survival, and side effects vary across tumor types but support PDT for the treatment of numerous solid tumors. With new advances in PDT, indications for this therapeutic modality may expand.

BackgroundImmune checkpoint inhibitors (ICIs) are approved to treat multiple cancers. Retrospective analyses demonstrate acceptable safety of ICIs in most patients with autoimmune disease, although disease exacerbation may occur. Psoriasis vulgaris is a common, immune-mediated disease, and outcomes of ICI treatment in patients with psoriasis are not well described. Thus we sought to define the safety profile and effectiveness of ICIs in patients with pre-existing psoriasis.MethodsIn this retrospective cohort study, patients from eight academic centers with pre-existing psoriasis who received ICI treatment for cancer were evaluated. Main safety outcomes were psoriasis exacerbation and immune-related adverse events (irAEs). We also assessed progression-free survival (PFS) and overall survival.ResultsOf 76 patients studied (50 (66%) male; median age 67 years; 62 (82%) with melanoma, 5 (7%) with lung cancer, 2 (3%) with head and neck cancer, and 7 (9%) with other cancers; median follow-up 25.1 months (range=0.2–99 months)), 51 (67%) received anti-PD-1 antibodies, 8 (11%) anti-CTLA-4, and 17 (22%) combination of anti-PD-1/CTLA-4. All patients had pre-existing psoriasis, most frequently plaque psoriasis (46 patients (61%)) and 15 (20%) with psoriatic arthritis. Forty-one patients (54%) had received any prior therapy for psoriasis although only two (3%) were on systemic immunosuppression at ICI initiation. With ICI treatment, 43 patients (57%) experienced a psoriasis flare of cutaneous and/or extracutaneous disease after a median of 44 days of receiving ICI. Of those who experienced a flare, 23 patients (53%) were managed with topical therapy only; 16 (21%) needed systemic therapy. Only five patients (7%) required immunotherapy discontinuation for psoriasis flare. Forty-five patients (59%) experienced other irAEs, 17 (22%) of which were grade 3/4. PFS with landmark analysis was significantly longer in patients with a psoriasis flare versus those without (39 vs 8.7 months, p=0.049).ConclusionsIn this multicenter study, ICI therapy was associated with frequent psoriasis exacerbation, although flares were manageable with standard psoriasis treatments and few required ICI discontinuation. Patients who experienced disease exacerbation performed at least as well as those who did not. Thus, pre-existing psoriasis should not prevent patients from receiving ICIs for treatment of malignancy.

IMPORTANCE Cutaneous immune-related adverse events (cirAEs) are some of the earliest toxic reactions to emerge following immune-checkpoint inhibitor (ICI) initiation. As an early indicator of robust inflammatory response, cirAEs may be associated with patterns of immune-mediated toxic effects, but associations between these events and noncutaneous immune-related adverse events (irAEs) remain underexplored.OBJECTIVES To characterize patterns of cirAEs and irAEs across care settings and examine associations between the features of first cirAE, overall irAE risk, and risk of specific irAE subtypes. DESIGN, SETTING, AND PARTICIPANTSA retrospective cohort study was conducted at a single academic medical center. The cohort included 358 patients with cancer who initiated anti-programmed death 1/ligand 1 and/or anticytotoxic-T-lymphocyte-4 ICI therapy between January 1, 2016, and March 8, 2019, and developed 1 or more cirAEs, identified using International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes and confirmed via manual medical record review. All relevant information documented before March 31, 2020, was included.EXPOSURES Anti-programmed death 1/ligand 1 and/or anticytotoxic-T-lymphocyte-4 therapy. MAIN OUTCOMES AND MEASURESAssociations between specific cirAE morphologic classes and patterns of irAEs (occurrence, timeline, organ class, and specific toxic effects). Given the potential that shared underlying factors are associated with the risk of both noncutaneous and cutaneous toxic effects, the presence of observed positive associations between certain cirAE and irAE subtypes was hypothesized. RESULTSOf the 358 patients, 213 were men (59.5%); median age was 65 years (interquartile range, 55-73 years). Nearly half of the patients (177 [49.4%]) with cirAE also developed a noncutaneous irAE. Most patients (128 [72.3%]) experienced their first cirAE before developing any irAE. Several cirAE morphologic classes were found to be associated with overall, organ-based, and specific irAEs. More specifically, mucositis was found to be associated with overall irAE risk (odds ratio [OR], 5.28; 95% CI, 1.11-24.26; P = .04), gastrointestinal irAEs (OR, 5.70; 95% CI,; P = .04), and the specific diagnosis of gastroenterocolitis (OR, 6.80; 95% CI, 1.24-37.39; P = .03). In addition, psoriasis was associated with an increased risk of endocrine irAEs (OR, 4.54; 95% CI, 1.21-17.04; P = .03). CONCLUSIONS AND RELEVANCEIn this cohort study, these findings underscore the risk of multisystem toxic effects in patients experiencing cirAEs and highlight potential opportunities for dermatologists in the management of noncutaneous toxic effects.

Background The aim of this study was to characterize severe immune‐related adverse events (irAEs) seen among hospitalized patients and to examine risk factors for irAE admissions and clinically relevant outcomes, including length of stay, immune checkpoint inhibitor (ICI) discontinuation, readmission, and death. Methods Patients who received ICI therapy (ipilimumab, pembrolizumab, nivolumab, atezolizumab, durvalumab, avelumab, or any ICI combination) at Massachusetts General Hospital (MGH) and were hospitalized at MGH following ICI initiation between January 1, 2011, and October 24, 2018, were identified using pharmacy and hospital admission databases. Medical records of all irAE admissions were reviewed, and specialist review with defined criteria was performed. Demographic data, relevant clinical history (malignancy type and most recent ICI regimen), and key admission characteristics, including dates of admission and discharge, immunosuppressive management, ICI discontinuation, readmission, and death, were collected. Results In total, 450 admissions were classified as irAE admissions and represent the study's cohort. Alongside the increasing use of ICIs at our institution, the number of patients admitted to MGH for irAEs has gradually increased every year from 9 in 2011 to 92 in 2018. The hospitalization rate per ICI recipient has declined over that same time period (25.0% in 2011 to 8.5% in 2018). The most common toxicities leading to hospitalization in our cohort were gastrointestinal (30.7%; n = 138), pulmonary (15.8%; n = 71), hepatic (14.2%; n = 64), endocrine (12.2%; n = 55), neurologic (8.4%; n = 38), cardiac (6.7%; n = 30), and dermatologic (4.4%; n = 20). Multivariable logistic regression revealed statistically significant increases in irAE admission risk for CTLA‐4 monotherapy recipients (odds ratio [OR], 2.02; p < .001) and CTLA‐4 plus PD‐1 combination therapy recipients (OR, 1.88; p < .001), relative to PD‐1/PD‐L1 monotherapy recipients, and patients with multiple toxicity had a 5‐fold increase in inpatient mortality. Conclusion This study illustrates that cancer centers must be prepared to manage a wide variety of irAE types and that CTLA‐4 and combination ICI regimens are more likely to cause irAE admissions, and earlier. In addition, admissions for patients with multi‐organ involvement is common and those patients are at highest risk of inpatient mortality. Implications for Practice  The number of patients admitted to Massachusetts General Hospital for immune‐related adverse events (irAEs) has gradually increased every year and the most common admissions are for gastrointestinal (30.7%), pulmonary (15/8%), and hepatic (14.2%) events. Readmission rates are high (29% at 30 days, 49% at 180 days) and 64.2% have to permanently discontinue immune checkpoint inhibitor therapy. Importantly, multiple concurrent toxicities were seen in 21.6% (97/450) of irAE admissions and these patients have a fivefold increased risk of inpatient death.