Risk of primary lung cancer after adjuvant radiotherapy in breast cancer-a large population-based study

Association of radiotherapy for prostate cancer and second primary colorectal cancer: a US population-based analysis

BACKGROUND

Radiotherapy (RT) is a common treatment for prostate cancer, yet the risk of second primary colorectal cancer (SPCRC) in patients with prostate cancer undergoing RT has not been adequately studied.

METHODS

This study employed a population-based cohort design using the US Surveillance, Epidemiology, and End Results (SEER) database to identify individuals diagnosed between January 1975 and December 2015. The cumulative incidence of SPCRC was estimated using Fine-Gray competing risk regression. Poisson regression analysis was used to estimate the risk associated with RT. Survival outcomes of patients with SPCRC were evaluated using the Kaplan-Meier method.

RESULTS

A total of 287,607 patients diagnosed with prostate cancer were identified. The cumulative incidences were higher in patients who did not receive RT (2.00%) compared to those who underwent RT (2.47%) after 25 years. After adjustment for multiple variables, RT was associated with an increased risk of developing combined SPCRC (adjusted HR 1.590). Additionally, the overall survival was significantly lower in patients who developed colorectal cancer after receiving RT as compared to those who did not receive RT.

CONCLUSION

These findings underscore the need for diligent long-term monitoring and effective management strategies to detect SPCRC in patients treated with RT for prostate cancer.

Dosimetry of intensity-modulated radiation therapy and volumetric-modulated arc therapy techniques after modified radical mastectomy for breast cancer and hypofractionated intensity-modulated radiotherapy

OBJECTIVE

The aim of this study was to compare the advantages and disadvantages of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) in patients with left-sided breast cancer who underwent hypofractionated IMRT after a modified radical mastectomy.

MATERIALS AND METHODS

Twenty patients who required adjuvant radiotherapy after modified radical mastectomy were randomly selected, and a specified dose of 43.5 Gy/15 F was used to plan for IMRT or VMAT. Dose-volume histograms (DVHs) were utilized to evaluate the dose distribution of the planning target volumes (PTVs) and organs at risk (OARs).

RESULTS

VMAT demonstrated a greater and more uniform dose distribution of PTVs and lower number of monitor units. No significant differences were found in V5 of the affected lung and heart between the two techniques (P > 0.05). The V10, V20, V30, and Dmean of the affected lung and V10, V20, V30, V40, Dmean, and Dmax of the whole heart were better in the VMAT than in the IMRT (P < 0.05). The Dmean and Dmax of the left anterior descending (LAD) branch of the coronary artery of the heart were better in the VMAT (P < 0.05), and the use of the VMAT effectively reduced the cardiopulmonary dose. A significant advantage of V30 and Dmean was also found in VMAT (P < 0.05).

CONCLUSION

These findings indicate that VMAT has higher clinical significance than IMRT, because it improved the dose distribution in the target area, reduced the cardiopulmonary dose, protected the OARs (e.g. thyroid), and shortened the treatment duration.

Risk of developing subsequent primary lung cancer after receiving radiation for breast cancer

Background

Radiotherapy (RT) is integral to breast cancer treatment, especially in the current era that emphasizes breast conservation. The aim of our study was to determine the incidence of subsequent primary lung cancer after RT exposure for breast cancer over a time span of 3 decades to quantify this risk over time as modern oncologic treatment continues to evolve.

Methods

The SEER (Surveillance, Epidemiology, and End Results) database was queried from 1988 to 2014 for patients diagnosed with nonmetastatic breast cancer. Patients who subsequently developed primary lung cancer were identified. Multivariable regression modeling was performed to identify independent factors associated with the development of lung cancer stratified by follow up intervals of 5 to 9 years, 10 to 15 years, and >15 years after breast cancer diagnosis.

Results

Of the 612,746 patients who met our inclusion criteria, 319,014 (52%) were irradiated. primary lung cancer developed in 5556 patients (1.74%) in the RT group versus 4935 patients (1.68%) in the non-RT group. In a multivariable model stratified by follow-up duration, the overall HR of developing subsequent ipsilateral lung cancer in the RT group was 1.14 (P = .036) after 5 to 9 years of follow-up, 1.28 (P = .002) after 10 to 15 years of follow-up, and 1.30 (P = .014) after >15 years of follow-up. The HR of contralateral lung cancer was not increased at any time interval.

Conclusions

The increased risk of developing a primary lung cancer secondary to RT exposure for breast cancer is much lower than previously published. Modern RT techniques may have contributed to the improved risk profile, and this updated study is important for counseling and surveillance of breast cancer patients.

Accelerated subsequent lung cancer after post-operative radiotherapy for breast cancer

BACKGROUND

Post-operative whole breast radiotherapy for breast cancer (BC) may increase the risk of subsequent lung cancer (LC). The impact of radiotherapy intensification (boost) has not been specifically explored in this context. We investigated the role of radiation modalities on the development of subsequent LC among our patients treated by radiotherapy for localized BC.

METHODS

All patients with a diagnosis of LC between 2000 and 2020 with a history of prior localized BC treated by surgery and post-operative radiotherapy were retrospectively reviewed. Primary endpoint was time to first diagnosis of LC after BC treatment with radiotherapy (RT).

RESULTS

From 98 patients who developed subsequent LC after primary BC treated with post-operative RT, 38% of patients (n = 37) received an additional RT boost, and 46% (n = 45) received hormonal treatment post radiation. A total of 61% (n = 60) were smokers. With regards to LC characteristics, adenocarcinoma was the most frequent histology (68%, n = 66); 36% (n = 35) harbored at least 1 molecular alteration, 57% (n = 20) of them being amenable to targeted therapy. Median time to first diagnosis of LC was 6 years [1.7-28.4 yrs] in the whole cohort. In the subgroup of patients treated with boost this time was reduced to 4 years [1.8-20.8 years] compared to 8 years for patients without boost [1.7-28.4 yrs] (p = 0.007). Boost, smoking usage, endocrine therapy, and age <50 yrs old at BC radiation remained independent factors associated with shorter time to first diagnosis of LC after BC treatment.

DISCUSSION

We report for the first time the potential impact of boost -part of BC radiation treatment- for BC on the risk of subsequent LC. The impact of low dose radiation on lung parenchyma could explain this phenomenon, but the underlying physiopathology is still under investigation. This work highlights the need for clinicians to identify patients at risk of developing faster subsequent thoracic malignancy after BC radiation, for implementing personalized surveillance.

Potential Applications of Nanoparticles in Improving the Outcome of Lung Cancer Treatment

Lung cancer is managed using conventional therapies, including chemotherapy, radiation therapy, or a combination of both. Each of these therapies has its own limitations, such as the indiscriminate killing of normal as well as cancer cells, the solubility of the chemotherapeutic drugs, rapid clearance of the drugs from circulation before reaching the tumor site, the resistance of cancer cells to radiation, and over-sensitization of normal cells to radiation. Other treatment modalities include gene therapy, immunological checkpoint inhibitors, drug repurposing, and in situ cryo-immune engineering (ICIE) strategy. Nanotechnology has come to the rescue to overcome many shortfalls of conventional therapies. Some of the nano-formulated chemotherapeutic drugs, as well as nanoparticles and nanostructures with surface modifications, have been used for effective cancer cell killing and radio sensitization, respectively. Nano-enabled drug delivery systems act as cargo to deliver the sensitizer molecules specifically to the tumor cells, thereby enabling the radiation therapy to be more effective. In this review, we have discussed the different conventional chemotherapies and radiation therapies used for inhibiting lung cancer. We have also discussed the improvement in chemotherapy and radiation sensitization using nanoparticles.

Cytotoxic Effects of Nanoliposomal Cisplatin and Diallyl Disulfide on Breast Cancer and Lung Cancer Cell Lines

Dual drug delivery has become the choice of interest nowadays due to its increased therapeutic efficacy in targeting the tumor site precisely. As quoted in recent literature, it has been known to treat several cancers with an acute course of action. Even so, its use is restricted due to the drug’s low pharmacological activity, which leads to poor bioavailability and increases first-pass metabolism. To overcome these issues, a drug delivery system using nanomaterials which would not only encapsulate the drugs of interest but also carry them to the target site of action is needed. Given all these attributes, we have formulated dual drug-loaded nanoliposomes with cisplatin (cis-diamminedichloroplatinum(II) (CDDP)), an effective anti-cancer drug, and diallyl disulfide (DADS), an organosulfur compound derived from garlic. The CDDP and DADS-loaded nanoliposomes (Lipo-CDDP/DADS) exhibited better physical characteristics such as size, zeta potential, polydispersity index, spherical shape, optimal stability, and satisfactory encapsulation percentage. The in vitro anti-cancer activity against MDA-MB-231 and A549 cell lines revealed that Lipo-CDDP/DADS showed significant efficacy against the cancer cell lines, depicted through cell nucleus staining. We conclude that Lipo-CDDP/DADS hold exceptional pharmacological properties with better anti-cancer activity and would serve as a promising formulation to treat various cancers.

Combined proton-photon treatment for breast cancer

Objective.Proton therapy remains a limited resource due to gantry size and its cost. Recently, a new design without a gantry has been suggested. It may enable combined proton-photon therapy (CPPT) in conventional bunkers and allow the widespread use of protons. In this work, we explore this concept for breast cancer.Methods.The treatment room consists of a LINAC for intensity modulated radiation therapy (IMRT), a fixed proton beamline (FBL) with beam scanning and a motorized couch for treatments in lying positions with accurate patient setup. Thereby, proton and photon beams are delivered in the same fraction. Treatment planning is performed by simultaneously optimizing IMRT and IMPT plans based on the cumulative dose. The concept is investigated for three breast cancers where the goal is to minimize mean dose to the heart and lung while delivering 40.05 Gy in 15 fractions to the PTV with a SIB of 48 Gy to the tumor bed. The probabilistic approach is applied to mitigate the sensitivity to range uncertainties.Results. CPPT is particularly advantageous for irradiating concave target volumes that wrap around a curved chest wall. There, protons may deliver dose to the peripheral and medial parts of the target volume including lymph nodes. Thereby, the mean dose in normal tissues is reduced compared to single-modality IMRT. However, tangential photon beams may treat parts of the target volume near the interface to the lung. To ensure target coverage for range undershoot in an IMPT plan, proton beams have to deliberately overshoot into the lung tissue-a problem that can be mitigated via the photon component which ensures plan conformity and robustness.Conclusion.CPPT using an FBL may represent a realistic approach to make protons available to more patients. In addition, CPPT may generally improve treatment quality compared to both single-modality proton and photon treatments.