Chemotherapy, molecular targeted therapy, and hormonal therapy are essential components of medical oncology. Al-though cancer patients significantly benefit from the emergence of various new anticancer drugs, none of these treatments can directly address drug resistance. Radiation therapy is one of the three conventional cancer treatment methods. Nearly two-thirds of cancer pa-tients accept radiation therapy during treatment. However, radiation resistance is a significant barrier affecting the therapeutic effect of this procedure. Epithelial–mesenchymal transition (EMT) is a biologic process that enables a polarized epithelial cell to undergo multi-ple biochemical changes. These changes enable the cell to assume the functions of a mesenchymal cell phenotype. These functions have been extensively studied and are related to embryogenesis, tumor invasiveness, and metastasis. In recent years, increasing evidence sug-gests that EMT is closely linked with tumor treatment resistance. The study of the relation between EMT and tumor treatment resistance is expected to contribute to the prevention of drug resistance and radiation resistance and thus improve treatment efficacy to provide benefit to cancer patients. This article explores this issue.

Small cell lung cancer ( SCLC ) is one common type of lung cancer in China. No remarkable progress has been made in systemic therapy for SCLC since the 90’ s. However, there are some advances in radiotherapy ( RT) for SCLC, which make it possible to improve treatment outcomes of SCLC. Those advances are mainly made in thoracic RT and prophylactic cranial irradiation for extensive?stage SCLC, radiation dose and technology of thoracic RT for limited?stage SCLC, and significance of prophylactic cranial irradiation for early?stage SCLC. The paper reviews the research advances in the East and West to provide some help and references for readers.

As a newly identified T helper cell subset, Th9 plays an important role in anti-tumor immunity. Th9 can be differentiated from CD4+T cells that have been induced by TGF-beta and IL-4. In addition, other CD4+T helper cell subsets can be developed to Th9 cell in particular situations, thereby showing its plasticity. Results of animal experiments have indicated that Th9 inhibits tumor growth and plays a significant role in anti-tumor immunity by secreting related cytokines such as IL-9. A few cytokines and molecules can regu-late the differentiation and development of Th9 cells in different signaling pathways. This review will focus on the production, anti-tu-mor immunity, related mechanism, and signaling pathways of Th9 cells, thereby providing a new field of vision and idea for anti-tumor therapy in the future.

Objective To evaluate the clinical efficacy and toxicities of radical intensity-modulated radiotherapy (IMRT) combined with reduction in dose of prophylactic irradiation in the treatment of stage Ⅲ small cell lung cancer (SCLC).Methods A retrospective analysis was performed on the clinical data of 40 patients with stage Ⅲ SCLC who were admitted from January 2010 to August 2012.The prescribed dose was 60 Gy in 30 fractions to the primary gross tumor volume and was 54 Gy in 30 fractions to the planning target volume.All patients received induction chemotherapy,31 patients received adjuvant chemotherapy,and 22 patients received concurrent chemoradiotherapy;the platinum-based chemotherapy combined with etoposide or teniposide was adopted.Prophylactic cranial irradiation (25 Gy in 10 fractions) was administered to 17 patients.The short-term tumor response was evaluated by RECIST 1.0,and radiation-related toxicities were assessed by CTCAE 4.0.Overall survival (OS),local recurrence-free survival (LRFS),and progression-free survival (PFS) were calculated by Kaplan-Meier method.Results The short-term tumor response rate was 98％.The follow-up rate was 100％.Twenty-two patients were followed up for at least 2 years.The 1-and 2-year OS rates were 84％ and 48％,respectively; the LRFS rates were 89％ and 85％,respectively; the PFS rates were 61％ and 41％,respectively.Grade 0-1 radiation-related pneumonia was observed in 65％(26/40) of all patients,grade 2 in 25％ (10/40),grade 3 in 5％ (2/40),and grade 5 in 5％ (2/40).Grade 0-1 radiation-related esophagitis was observed in 53％ (21/40) of all patients,grade 2 in 43％ (17/40),and grade 3 in 5 ％ (2/40).Conclusions Preliminary results from this study suggested that IMRT combined with reduction in dose of prophylactic irradiation is safe and effective in patients with stage Ⅲ SCLC and is worth further evaluation in a large,prospective,randomized study.

Peritumoral edema (PTE) of the metastasis tumor of brain (MTB) refers to the abnormal increase of moisture in the surrounding cerebral parenchyma of the brain tumor. The mechanism of PTE occurrence of MTB is complicated, and the influencing factors are diverse. PTE is one of the key factors that affect patient survival and cure. Researchers from China and overseas believe that it may be related to the expression of the vascular endothelial growth factor (VEGF) or VEGF receptor, aquaporin-4 (AQP-4), matrix metalloproteinase-9, interleukin-6, hypoxia inducible factor-1a, and other molecular biology factors. Studies of these molecular biologi-cal factors provide objective scientific evidence for the prevention, control, monitoring, treatment, and prognosis of PTE of metasta-sized brain tumor. In addition to the traditional dehydration therapy of PTE, the use of PTE-related molecular biological factors pro-vides a new approach for the treatment. AQP-4 agonists or antagonists and VEGF receptor antagonists also have good therapeutic poten-tials. In this paper, the authors reviewed the PTE-related molecular biological factors of MTB.

The current challenge from radiotherapy of early breast cancer has been to minimize the morbidity caused by this treatment without losing efficacy.Conventional two-dimensional radiotherapy breast plans can produce substantial dose inhomogeneities.Intensity-modulated radiotherapy(IMRT) can be used to improve the dose homogeneity in an irradiated volume.And to some extent,IMRT can reduce radiation doses to adjacent normal tissues including the contralateral breast,heart and lung,and improve the cosmetic outcome.

Objective To explore the reasonable radiotherapy range by analyzing the patterns and characteristics of intra-thoracic lymph node metastasis in small cell lung cancer (SCLC).Methods One hundred and fifty patients with limited-stage SCLC who received radical resection of primary tumor and systemic intra-thoracic lymph node dissection were included in the study.All the lymph nodes in each area were recorded and examined pathologically to analyze the patterns and characteristics of intra-thoracic lymph node metastasis.Results A total of 2372 lymph nodes were found in 631 areas,and a total of 413 positive lymph nodes (17.4％) were found in 188 lymph node areas (29.8％ ).Intra-thoracic lymph node metastasis were found in 88 patients,with a positive rate of 58.7％.The frequencies of metastasis in the area 11,10,7,5,4 were much higher than those in the other areas,and central located lesions and the higher T-stage lung tumors were more likely to develop intra-thoracic lymph node metastasis (x2 =15.32,39.72;P =0.000,0.000,respectively).Tumors located in the right upper lobe and right middle/lower lobe had a higher tendency of metastasis to the areas 4,7,10 and 4,7,10,11,respectively.Tumors located in the left upper lobe and left lower lobe had a higher tendency of metastasis to the areas 4,5,6,10 and 4,7,9,10,11,respectively.Mediastinal lymph node metastasis (N2 ) were found in 72 patients,among whom 29 patients (40.3％ ) had skipping N2 metastasis without hilar metastasis.Tumors located in the upper lobe had a tendency of skipping metastasis to the upper mediastinum,while tumors located in the middle/lower lobe had a tendency of skipping metastasis to the upper and lower mediastinum.Conclusions The lymph node metastases in SCLC follow the lymphatic drainage routes,that is,from intrapulmonary to the hilar and then to the mediastinum,but with some skipping metastases.Tumors located in different lobes have different high risk lymph node areas for metastasis,and elective irradiation to these lymph node areas maybe increase radiotherapy gain ratio in SCLC.

Radiotherapy is important for cancer treatment. However, some patients still experience relapse and exhibit radiation resistance. Mammalian target of rapamycin (mTOR) is the main effector molecule in PI3K/AKT signaling. This molecule is found in two structurally and functionally distinct multi-protein complexes known as the mTOR complex 1 and mTOR complex 2. The mTOR signaling pathway controls the growth, proliferation, survival, and apoptosis of cancer cells. This pathway is closely related to tumori-genesis and treatment response, and is used in sensitizing radiotherapy. mTOR inhibitors regulate radio-sensitization through multiple mechanisms, including cell cycle alterations, DNA repair modulation, and tumor hypoxia reduction. Preclinical studies showed that mTOR inhibitors with tolerable toxicity may be used as an effective modality to overcome radio-resistant tumors. Responses to mTOR inhibitors vary depending on the cell lines. Molecular markers can be used to select suitable patients. Further studies are needed to com-pletely understand the use of mTOR inhibitors in radio-sensitization.

Objective To evaluate the influence of respiration on the radiation dose distribution within target volume in radiotherapy with film dosimetry. Methods Radiation of 50 MU was delivered by a square, round, ellipse, dumb bell, or female shaped filed to the films within a moving or motionless Respiration Motion Phantom respectively, the dose distributions for the two motion status were measured and compared. In order to further verify the impact of respiration, a plank phantom was used on different shifting value: 0, 0.5, 1.0, 1.5 and 2.0 cm, respectively. A square, round, or eUipse-shaped filed was used for irradiation and the distributions in different status were measured and compared with film dosimetry. Iso-dose line comparison, NAT(Normalized Agreement Tests) and γ comparison were used for the comparison of dose distributions. Fs can be an index to reflect the variability of the areas that surrounded by iso-dose lines. (FS90, FS50, FS25 delegates the ratio of the areas that surrounded by 90 %,50 %,25 % iso-dose hne in different situation respectively). Results (1) Compared with motionless situation, the FS90 in horizontal movement situation became small and the FS25 became large. As the displacement became larger, the FS90 became larger and the FS25 became smaller. FS in vertical movement situation, square and dumb bell fields changed while the others didn't have a change. (2)γ and NAT comparison: In the horizontal movement situation, compared with the static phantom, Pγ < 60 % and PNAT < 75 %. Under vertical movement situation, Pγ were less than 85 % for the square, round, dumb bell and female shaped fileds. In the plank phantom verification, Pγ and PNAT became smaller as the movement became larger. Conclusions The respiration can impact on the dose distribution within the target volume in radiotherapy, leading to a smaller area of higher dose level and an expanded area of lower dose level. The influence will become more significant with larger movement of the target.