Cellular signaling and epigenetic regulation of gene expression in leukemia

Alterations in normal regulation of gene expression is one of the key features of hematopoietic malignancies. In order to gain insight into the mechanisms that regulate gene expression in these diseases, we dissected the role of the Ikaros protein in leukemia. Ikaros is a DNA-binding, zinc finger protein that functions as a transcriptional regulator and a tumor suppressor in leukemia. The use of ChIP-seq, RNA-seq, and ATAC-seq—coupled with functional experiments—revealed that Ikaros regulates both the global epigenomic landscape and epigenetic signature at promoter regions of its target genes. Casein kinase II (CK2), an oncogenic kinase that is overexpressed in leukemia, directly phosphorylates Ikaros at multiple, evolutionarily-conserved residues. Phosphorylation of Ikaros impairs the protein's ability to regulate both the transcription of its target genes and global epigenetic landscape in leukemia. Treatment of leukemia cells with a specific inhibitor of CK2 restores Ikaros function, resulting in cytotoxicity of leukemia cells. Here, we review the mechanisms through which the CK2-Ikaros signaling axis regulates the global epigenomic landscape and expression of genes that control cellular proliferation in leukemia.

Abstract 2620: Global epigenetic regulation of gene expression and tumor suppression in T-cell leukemia by Ikaros

Ikaros encodes a DNA-binding zinc finger protein that functions as a tumor suppressor. Loss of Ikaros function results in the development of high-risk B-cell and T-cell acute lymphoblastic leukemia. Previous studies suggested that Ikaros controls expression of its target genes via chromatin remodeling, and by forming complexes with the histone deacetylase, HDAC1. However, the mechanisms through which Ikaros regulates the global epigenetic signature in leukemia is unknown. We studied the role of Ikaros in regulating tumor suppression in Ikaros-defficient T-cell acute lymphoblastic leukemia (T-ALL) cells. The re-introduction of Ikaros at physiological levels via retroviral transduction into T-ALL cells, results in a cessation of cellular proliferation and cell cycle arrest within 4 days. To determine the dynamics of Ikaros-mediated epigenetic regulation of gene expression in T-ALL, we performed ChIP-seq of Ikaros, HDAC1, and histone modifications, along with microarray and ATAC-seq in wild-type T-ALL (that lacks Ikaros), and during each of 3 days following the re-introduction of Ikaros. Our results demonstrated that Ikaros directly regulates the global epigenomic landscape including genome wide de novo formation of enhancers in T-ALL. Further analysis showed that Ikaros induces the re-distribution of HDAC1 via direct recruitment of HDAC1 to promoter and enhancer regions of different target genes resulting in their transcriptional repression. Expression analysis identified a large number of novel signaling pathways that are directly regulated by Ikaros and HDAC1, and are responsible for the cessation of proliferation and the cell cycle arrest of T-ALL cells. Our results identified novel functions of Ikaros in the epigenetic regulation of gene expression and tumor suppression in T-ALL.

Citation Format: Yali Ding, Bo Zhang, Jonathon L. Payne, Kimberly J. Payne, Chunhua Song, Chandrika Gowda, Soumya Iyer, Pavan K. Dhanyamraju, Dhimant Desai, Suming Huang, Feng Yue, Sinisa Dovat. Global epigenetic regulation of gene expression and tumor suppression in T-cell leukemia by Ikaros [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2620.

Short duration of untreated psychosis enhances negative symptom remission in extended early intervention service for psychosis

OBJECTIVE

To test whether duration of untreated psychosis (DUP) < 3 months, recommended by the World Health Organization/International Early Psychosis Association, enhances the effects of an extended early intervention service (EEIS) on symptom remission.

METHOD

We examined data from a randomized controlled trial in which patients who received 2 years of treatment in EIS for psychosis were subsequently randomized to either 3 years of EEIS or 3 years of regular care (RC). Using a DUP cut-off ≤ 12 weeks (approximately < 3 months), patients were split into two groups. Length of positive, negative and total symptom remission were the outcomes.

RESULTS

Patients (N = 217) were mostly male (68%) with schizophrenia spectrum disorder (65%); 108 (50%) received EEIS (58 had DUP ≤12 weeks; 50 had DUP >12 weeks). Interaction between treatment condition (EEIS vs. RC) and DUP cut-off ≤ 12 weeks was only significant in multiple linear regression model examining length of negative symptom remission as the outcome (adjusted β = 36.88 [SE = 15.88], t = 2.32, P = 0.02). EEIS patients with DUP ≤12 weeks achieved 25 more weeks of negative symptom remission than EEIS patients with DUP >12 weeks.

CONCLUSION

Having a short DUP may be critical in deriving long-term benefits from EIS for psychosis, including EEIS settings. This work empirically supports policy recommendations of reducing DUP <3 months.

The novel Isatin analog KS99 targets stemness markers in acute myeloid leukemia

Leukemic stem cells are multipotent, self-renewing, highly proliferative cells that can withstand drug treatments. Although currently available treatments potentially destroy blast cells, they fail to eradicate leukemic progenitor cells completely. Aldehyde dehydrogenase and STAT3 are frequently up-regulated in pre-leukemic stem cells as well as in acute myeloid leukemia (AML) expressing the CD34⁺CD38⁻ phenotype. The Isatin analog, KS99 has shown anticancer activity against multiple myeloma which may, in part, be mediated by inhibition of Bruton’s tyrosine kinase activation. Here we demonstrate that KS99 selectively targets leukemic stem cells with high aldehyde dehydrogenase activity and inhibits phosphorylation of STAT3. KS99 targeted cells co-expressing CD34, CD38, CD123, TIM-3, or CD96 immunophenotypes in AML, alone or in combination with the standard therapeutic agent cytarabine. AML with myelodysplastic-related changes was more sensitive than de novo AML with or without NPM1 mutation. KS99 treatment reduced the clonogenicity of primary human AML cells as compared to normal cord blood mononuclear cells. Downregulation of phosphorylated Bruton’s tyrosine kinase, STAT3, and aldehyde dehydrogenase was observed, suggesting interaction with KS99 as predicted through docking. KS99 with or without cytarabine showed in vivo preclinical efficacy in human and mouse AML animal models and prolonged survival. KS99 was well tolerated with overall negligible adverse effects. In conclusion, KS99 inhibits aldehyde dehydrogenase and STAT3 activities and causes cell death of leukemic stem cells, but not normal hematopoietic stem and progenitor cells.

Ikaros tumor suppressor function includes induction of active enhancers and super-enhancers along with pioneering activity

Ikaros encodes a transcription factor that functions as a tumor suppressor in T-cell acute lymphoblastic leukemia (T-ALL). The mechanisms through which Ikaros regulates gene expression and cellular proliferation in T-ALL are unknown. Re-introduction of Ikaros into Ikaros-null T-ALL cells resulted in cessation of cellular proliferation and induction of T-cell differentiation. We performed dynamic, global, epigenomic and gene expression analyses to determine the mechanisms of Ikaros tumor suppressor activity. Our results identified novel Ikaros functions in the epigenetic regulation of gene expression: Ikaros directly regulates de novo formation and depletion of enhancers, de novo formation of active enhancers and activation of poised enhancers; Ikaros directly induces the formation of super-enhancers; and Ikaros demonstrates pioneering activity by directly regulating chromatin accessibility. Dynamic analyses demonstrate the long-lasting effects of Ikaros DNA binding on enhancer activation, de novo formation of enhancers and super-enhancers, and chromatin accessibility. Our results establish that Ikaros’ tumor suppressor function occurs via global regulation of the enhancer and super-enhancer landscape and through pioneering activity. Expression analysis identified a large number of novel signaling pathways that are directly regulated by Ikaros and Ikaros-induced enhancers, and that are responsible for the cessation of proliferation and induction of T-cell differentiation in T-ALL cells.

Clinical considerations of the role of palbociclib in the management of advanced breast cancer patients with and without visceral metastases

Background

This report assesses the efficacy and safety of palbociclib plus endocrine therapy (ET) in women with hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer (ABC) with or without visceral metastases.

Patients and methods

Pre- and postmenopausal women with disease progression following prior ET (PALOMA-3; N = 521) and postmenopausal women untreated for ABC (PALOMA-2; N = 666) were randomized 2 : 1 to ET (fulvestrant or letrozole, respectively) plus palbociclib or placebo. Progression-free survival (PFS), safety, and patient-reported quality of life (QoL) were evaluated by prior treatment and visceral involvement.

Results

Visceral metastases incidence was higher in patients with prior resistance to ET (58.3%, PALOMA-3) than in patients naive to ET in the ABC setting (48.6%, PALOMA-2). In patients with prior resistance to ET and visceral metastases, median PFS (mPFS) was 9.2 months with palbociclib plus fulvestrant versus 3.4 months with placebo plus fulvestrant [hazard ratio (HR), 0.47; 95% confidence interval (CI), 0.35–0.61], and objective response rate (ORR) was 28.0% versus 6.7%, respectively. In patients with nonvisceral metastases, mPFS was 16.6 versus 7.3 months, HR 0.53; 95% CI 0.36–0.77. In patients with visceral disease and naive to ET in the advanced disease setting, mPFS was 19.3 months with palbociclib plus letrozole versus 12.9 months with placebo plus letrozole (HR 0.63; 95% CI 0.47–0.85); ORR was 55.1% versus 40.0%; in patients with nonvisceral disease, mPFS was not reached with palbociclib plus letrozole versus 16.8 months with placebo plus letrozole (HR 0.50; 95% CI 0.36–0.70). In patients with prior resistance to ET with visceral metastases, palbociclib plus fulvestrant significantly delayed deterioration of QoL versus placebo plus fulvestrant, whereas patient-reported QoL was maintained with palbociclib plus letrozole in patients naive to endocrine-based therapy for ABC.

Conclusions

Palbociclib plus ET prolonged mPFS in patients with visceral metastases, increased ORRs, and in patients previously treated for ABC, delayed QoL deterioration, presenting a standard treatment option among patients with visceral metastases amenable to endocrine-based therapy.

Clinical trial registration

NCT01942135, NCT01740427

Palbociclib plus letrozole as first-line therapy in estrogen receptor-positive/human epidermal growth factor receptor 2-negative advanced breast cancer with extended follow-up

PURPOSE

In the initial PALOMA-2 (NCT01740427) analysis with median follow-up of 23 months, palbociclib plus letrozole significantly prolonged progression-free survival (PFS) in women with estrogen receptor-positive (ER+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) [hazard ratio (HR) 0.58; P < 0.001]. Herein, we report results overall and by subgroups with extended follow-up.

METHODS

In this double-blind, phase 3 study, post-menopausal women with ER+/HER2- ABC who had not received prior systemic therapy for their advanced disease were randomized 2:1 to palbociclib-letrozole or placebo-letrozole. Endpoints include investigator-assessed PFS (primary), safety, and patient-reported outcomes (PROs).

RESULTS

After a median follow-up of approximately 38 months, median PFS was 27.6 months for palbociclib-letrozole (n = 444) and 14.5 months for placebo-letrozole (n = 222) (HR 0.563; 1-sided P < 0.0001). All subgroups benefited from palbociclib treatment. The improvement of PFS with palbociclib-letrozole was maintained in the next 2 subsequent lines of therapy and delayed the use of chemotherapy (40.4 vs. 29.9 months for palbociclib-letrozole vs. placebo-letrozole). Safety data were consistent with the known profile. Patients' quality of life was maintained.

CONCLUSIONS

With approximately 15 months of additional follow-up, palbociclib plus letrozole continued to demonstrate improved PFS compared with placebo plus letrozole in the overall population and across all patient subgroups, while the safety profile remained favorable and quality of life was maintained. These data confirm that palbociclib-letrozole should be considered the standard of care for first-line therapy in patients with ER+/HER2- ABC, including those with low disease burden or long disease-free interval. Sponsored by Pfizer; ClinicalTrials.gov: NCT01740427.

Abstract P6-18-36: Real world treatment patterns and outcomes of patients receiving palbociclib plus aromatase inhibitor in the United States: Sub-groups analysis based on age, performance status and sites of metastases from the IRIS study

Background: Ibrance Real World Insights (IRIS) is a multi-country study aimed to describe clinical characteristics, treatment patterns and clinical outcomes of patients receiving palbociclib plus aromatase inhibitor. Previously the results on the overall population within the US have been communicated. The current analysis focuses on subgroups stratified by age, performance status and visceral status.

Materials and methods: A retrospective chart review of HR+/HER2- ABC/MBC patients who received palbociclib plus aromatase inhibitor as initial endocrine based therapy for their advanced disease was conducted between June and October 2017. Physicians completed electronic case report forms, extracting data on patient demographics, clinical characteristics, treatment history/patterns and clinical outcomes.Progression free and survival rates at 12 and 24 months were estimated via Kaplan-Meier analysis.

Results: Data for the US are reported here. In total 63 physicians completed 360 eCRFs with a mean follow up time since palbociclib initiation of 12 months. Majority of the patients were &gt;65 years (53%), and had ECOG status of 0 (30%) or 1 (56%). Overall 293 (81%) patients had metastatic disease, of which 50% had visceral metastases. Across all sub-groups, majority of patients prescribed an initial palbociclib dose of 125mg did not require a change of dose while on treatment. The 12-month and 24-month progression free and overall survival rates across subgroups are presented in Table 1. Patients with a performance status of ECOG=1 had a slightly lower progression and survival rates at 12 and 24 months compared to those with a score =0. Likewise, patients with visceral disease were observed to have slightly lower progression free and survival rates than others.

Table 1:Clinical Outcomes for the different sub-groups.Patient Sub-groups AgeECOG statusVisceral Status Up to 65 n=169Over 65 n=1910 n=1071 n=200Visceral metastases n=147Non-visceral metastases n=146Progression free survival rate at 12 months, %86.382.194.386.580.285.8Progression free survival rate at 24 months, %59.769.071.267.450.780.6Overall survival rate At 12 months, %97.992.8100.099.590.599.3Overall survival rate at 24 months, %95.185.695.796.487.290.7

Conclusions: The analysis indicates consistent trends in different clinical outcomes were observed with palbociclib plus aromatase inhibitor across patients sub-groups based on age, performance status and visceral metastases.

Citation Format: Taylor-Stokes G, Mitra D, Waller J, Gibson K, Milligan G, Zhan L, Iyer S. Real world treatment patterns and outcomes of patients receiving palbociclib plus aromatase inhibitor in the United States: Sub-groups analysis based on age, performance status and sites of metastases from the IRIS study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-36.

Abstract P6-18-29: Real-world treatment patterns and clinical outcomes with palbociclib combination therapy received in US community oncology practices

Background:

The treatment landscape for women with HR+/HER2- advanced and metastatic breast cancer (A/MBC) is changing as new agents are being combined with more established treatments to achieve greater efficacy in combating resistant and unresponsive disease. The present study is designed to describe patient characteristics, treatment patterns, and clinical outcomes in a cohort of women with HR+/HER2- A/MBC treated with palbociclib plus aromatase inhibitor (P+AI) or palbociclib plus fulvestrant (P+FV) in the US community oncology setting.

Methods:

Retrospective medical record data from adult women diagnosed with HR+/HER2- A/MBC who initiated P+AI or P+FV for treatment of A/MBC on or after February 3, 2015 were collected from the Vector Oncology Data Warehouse, a network comprised of 10 community oncology practices across the US. Descriptive analyses were performed on patient characteristics, treatment patterns, and clinical outcomes. Time to event outcomes (progression-free rate (PFR) and survival rate (SR)) at 12 (PFR-12, SR-12) and 24 (PFR-24, SR-24) months for the P+AI combination as first line endocrine therapy and 12 and 18 months for the P+FV combination as treatment following prior endocrine based therapy in either the adjuvant or metastatic setting.

Results:

Among 304 patients who received palbociclib combination therapy, 281 (92.4%) received it per labeled indication. Of the 281 on-label users, the focus of reporting here, 233 (82.9%) received P+AI as their initial endocrine therapy after A/MBC diagnosis; 48 (17.1%) received P+FV after prior endocrine therapy for breast cancer. Patient mean age (SD) was 63.1 (11.4) and 68.2 (10.2) years for patients receiving P+AI and P+FV, respectively. Patients were predominantly white (74.2% for P+AI and 77.1% for P+FV patients).The initial dosing for palbociclib was 125mg/day in 85.4% (n=199) of P+AI and 79.2% (n=38) of P+FV patients. Among patients who received P+AI, PFR-12 was 69.8% and PFR-24 was 46.8% with median follow up time of 10.8 months and 36.8% of progression events. The SR-12 was 89.8% and SR-24 was 71.4%. For patients who received P+FV, PFR-12 was 43.5% and PFR-18 was 39.9% with a median follow up time of 7.6 months and 50.0% of progression events. The SR-12 was 76.3% and SR-18 was 65.0%.

Conclusions:

This study provides real-world assessment of treatment patterns and clinical outcomes of patients with HR+/ HER2- A/MBC who received palbociclib in combination with an AI or a FV in US community oncology settings. These findings demonstrate the benefit of palbociclib combination therapy in a diverse real world population.

Sponsor: Pfizer, Inc.

Citation Format: Trocio J, Lin J, Fisher MD, Hu N, Davis C, McRoy L, Walker MS, Iyer S. Real-world treatment patterns and clinical outcomes with palbociclib combination therapy received in US community oncology practices [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-29.

Abstract P6-18-33: GI toxicities in metastatic breast cancer: A comprehensive literature review

Background

Treatments for advanced or metastatic breast cancer (aBC/mBC) are associated with gastrointestinal (GI) toxicities. The objective of this study was to assess the association between GI toxicities in mBC/aBC and health-related quality of life (HRQoL) and economic burden.

Methods

We conducted a comprehensive literature search of the Cochrane Central Register of Controlled Trials (2017), NHS Economic Evaluation Database (2016), Embase (1988 – 2017 week 34), and Ovid MEDLINE (1946 to August 2017). Eligible studies evaluated an intervention/comparator treatment in adult patients (age ≥18 years) with aBC/mBC and reported a direct connection between GI toxicities (ie, diarrhea, constipation, nausea, vomiting) and HRQoL and economic evidence. All studies published from January 2000 to August 2017 were assessed for eligibility. Editorials, case reports, conference abstracts, and studies of early, locally advanced, or inflammatory BC were excluded. Abstract and title screening, and full-text screening were conducted by single reviewers. Data were extracted by a single reviewer and verified by a second. Results were synthesized narratively.

Results

Database searches identified 3,428 articles; an additional 16 articles were identified through other sources. Ninety-four studies underwent full-text review, of which 27 reported a direct connection between GI toxicities and HRQoL (n = 11) and economic burden (n = 19). Some studies reported both HRQoL and economic data.

Patients identified treatment-related adverse events (AEs), such as GI events, as an important aspect of treatment that can affect therapy choice, discontinuation, and switching. Generally, patients with mBC had lower HRQoL than other BC groups, and increasing toxicity was associated with a greater degree of HRQoL impairment. When patients were asked to rank which AEs they most wanted to avoid, only pain ranked higher than nausea and vomiting. In a willingness to pay study, women with mBC were willing to pay $3,894 (2014 USD) per year to avoid severe diarrhea and $3,211 to avoid severe nausea.

Gastrointestinal events were among the costliest class of AEs, with mean costs as high as $4,809 (2016 USD) per episode; costs increased by 24% if events were persistent or recurrent.

Conclusions

Gastrointestinal toxicities are common in patients with aBC/mBC and have significant consequences for HRQoL and system-level economic outcomes. Frequency and implications of GI effects of treatment regimens should be considered carefully during patient counseling,, prescribing and coverage decisions in metastatic breast cancer.

Citation Format: Disher T, Siddiqui M, Mitra D, Cameron C, Zhan L, Iyer S. GI toxicities in metastatic breast cancer: A comprehensive literature review [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-33.

Abstract P6-18-21: Real world treatment patterns and outcomes of patients receiving palbociclib plus fulvestrant in the United States: Sub-groups analysis based on age, performance status and sites of metastases

Background: Ibrance Real World Insights (IRIS) is a multi-country study aimed to describe the clinical characteristics and understand treatment patterns and clinical outcomes of patients receiving palbociclib plus fulvestrant in real world clinical practice. Previously the results on the overall population within the US have been communicated. The current analyses focus on subgroups stratified by age, performance status and visceral status.

Materials and methods: A retrospective chart review of HR+/HER2- ABC/MBC patients was conducted between June and October 2017. Physicians extracted data from patient medical records for HR+/HER2- ABC patients who received palbociclib plus fulvestrant following disease progression with endocrine based therapy for their advanced disease. Electronic case report forms collected data covering patient demographics, clinical characteristics, treatment history/patterns and clinical outcomes.Progression free rates and survival rates at 6 and 12 months were estimated via Kaplan-Meier analysis.

Results: Data for the US are reported here. In total, 65 physicians extracted data for 292 patients who had a mean follow up time of 7.4 months. Majority of the patients were &gt;65 years (54%), and had ECOG status of 0 (32%) or 1 (48%). Overall 224 (77%) patients had metastatic disease, of which 93 (42%) had visceral metastases. Across all sub-groups, majority of patients prescribed an initial palbociclib dose of 125mg did not require a change of dose while on treatment. The 6-month and 12-month progression free and survival rates across subgroups are presented in Table 1. Patients with a performance status of ECOG ≥ 2 had a slightly lower progression and survival rates at 6 and 12 months compared to those with a score &lt;1. Likewise, patients with visceral disease were observed to have slightly lower progression free and survival rates than others.

Table 1:Clinical Outcomes by Patient Sub-groups.Patient Sub-groups AgeECOGstatusVisceral Status Up to 65 n=158Over 65 n=1340 n=931 n=1392+ n=60Visceral Metastases n=93Non-visceral Metastases n=131Progression free survival rate at 6 months, %95.293.297.893.490.689.694.8Progression free survival rate at 12 months, %81.277.884.683.0-73.276.5Survival rate at 6 months, %98.096.3100.098.290.692.298.9Survival rate at 12 months, %90.085.197.695.1-80.892.7

Conclusions: The analysis indicates consistent trends in different clinical outcomes were observed with palbociclib plus fulvestrant across patients sub-groups based on age, performance status and visceral metastases.

Citation Format: Waller J, Mitra D, Taylor-Stokes G, Gibson K, Milligan G, Zhan L, Iyer S. Real world treatment patterns and outcomes of patients receiving palbociclib plus fulvestrant in the United States: Sub-groups analysis based on age, performance status and sites of metastases [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-18-21.

Impact of postoperative radiotherapy on survival and loco-regional control in node-negative oral cavity tumours classified as T3 using the AJCC Cancer Staging Manual eighth edition

According to the eighth edition of the AJCC Cancer Staging Manual (AJCC8), a depth of invasion (DOI) >10mm is classified as pT3, representing a locally advanced tumour requiring postoperative radiotherapy (PORT). When node-negative, however, evidence regarding whether PORT improves loco-regional control or survival is unclear. To clarify this, two cohorts of patients were studied: (1) patients classified as pT3N0 by the seventh edition of the AJCC manual (AJCC7), with DOI >10mm and a tumour diameter >4cm (17 patients who received PORT), and (2) patients classified as pT1N0 and pT2N0 by AJCC7, with DOI >10mm and a tumour diameter <4cm (55 patients who did not receive PORT). Loco-regional control and survival were analysed. PORT was found not to impact overall survival or disease-free survival. It was also found not to impact local, regional, or distant recurrence. Although the two subsets of patients considered here (DOI >10mm with tumour diameter below or above 4cm) were previously distinct, they are both considered pT3 in AJCC8. Data from this study indicate that the routine administration of PORT to patients with a DOI >10mm may not be warranted in the absence of other risk features such as nodal disease or close margins.

Is pulmonary metastasectomy beneficial in head and neck squamous cell carcinoma? A review of literature

Metastatic head and neck squamous cell carcinoma (HNSCC) has traditionally carried a dismal prognosis; however with advances in care, it has been shown that pulmonary metastasectomy is a viable therapeutic option in selected patients, palliating symptoms and improving survival. With the increasing incidence of human papilloma virus-related HNSCC and better availability of minimal access surgery, there is a need to better understand the role of pulmonary metastasectomy in the treatment of HNSCC. This article summarizes the literature on indications, results, surgical options and approaches, clinical dilemmas, and controversies associated with pulmonary metastasectomy in HNSCC, to identify suitable candidates and optimize outcomes.