Clinical T1N0 Research Articles

Does one size fit all? Risks and benefits of neoadjuvant chemoradiation in patients with clinical stage IIA rectal cancer requiring abdominoperineal resection

BackgroundNeoadjuvant chemoradiotherapy (nCRT) has become the standard of care for locally advanced rectal cancer, decreasing locoregional recurrence, yet with an unclear survival advantage. We aimed to assess the benefit of nCRT on oncologic and perioperative outcomes of patients with clinical stage IIA rectal adenocarcinoma treated with abdominoperineal resection (APR). MethodsPatients with clinical T3N0 rectal adenocarcinoma that underwent APR between 1995 and 2014 were included. Patients who received nCRT were compared with patients who did not. Multivariate analysis was conducted to compare oncological and perioperative outcomes between the groups. Results127 patients were included, of which 94 received nCRT. Median follow-up was 11.9 years. There was no difference in circumferential margins, postoperative morbidity, and complication rates between the groups. There was no difference in 5-year oncological outcomes between the groups. ConclusionsNo difference was found in 5-year oncological outcomes between patients with clinical T3N0 rectal adenocarcinoma necessitating an APR who received nCRT and those not receiving nCRT, with similar overall complication rates.

MS07.04 Stage I (Resectable) NSCLC: Surgery

MS07.04 Stage I (Resectable) NSCLC: Surgery

Chemoradiotherapy for Esophageal Cancer

Esophageal cancer is a highly lethal malignancy. Squamous cell cancer (SCC) and adenocarcinoma are two major histologic types of esophageal cancer. The therapeutic approaches for both histologic types tend to be similar. Endoscopic therapy is considered in patients with Tis and T1a, and surgery alone is recommended in patients with T1N0 esophageal SCC or adenocarcinoma. Definitive chemoradiotherapy is a reasonable option for patients unable to withstand surgery. Esophagectomy is considered as the initial treatment for patients with clinical T2N0 esophageal SCC and those with adenocarcinoma with low lymph node metastasis risk. Combined modality therapy is recommended for patients with T3N0, T4aN0, and clinically node-positive thoracic esophageal cancer, regardless of histology. Definitive concurrent chemoradiotherapy is the most appropriate treatment approach for patients with esophageal SCC who are not surgical candidates. Definitive concurrent chemoradiotherapy is also considered for esophageal SCC patients who are potential surgical candidates with an endoscopically documented complete response after neoadjuvant chemoradiotherapy. For chemoradiotherapy non-responders, surgery is recommended for those who remain operable after chemoradiotherapy. Esophagectomy is also recommended for patients with esophageal adenocarcinoma after neoadjuvant chemoradiotherapy. Definitive concurrent chemoradiotherapy is preferred over surgery in patients with cervical esophageal cancer because its survival rate is similar to that of surgery and major morbidity can be avoided. Concurrent chemoradiotherapy rather than radiation therapy alone is recommended for patients who can tolerate this approach for non-metastatic, inoperable, or unresectable esophageal SCC or adenocarcinoma. Key words: Chemoradiotherapy; Drug therapy; Esophageal neoplasms; Therapeutics

Nodal Metastasis in Oral Squamous Cell Carcinoma: Predictive Impact of MRI-Derived Depth of Invasion According to the 8th Edition American Joint Committee on Cancer Staging System

To evaluate the relationship between the magnetic resonance imaging (MRI)-derived depth of invasion (DOI) and nodal recurrence in clinically node-negative patients with oral squamous cell carcinoma (SCC). The institutional review board approved this retrospective study. The study population consisted of 90 patients with clinical T1-2N0 oral SCC classified according to the 7th edition American Joint Committee on Cancer (AJCC) staging system; 41 were staged as T1N0 and 49 as T2N0. They (55 males and 35 females; median age, 70 years; age range, 29 - 92 years) had undergone routine pretreatment radiological examinations including MRI and 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) fused imaging. The clinical pretreatment stage had been identified at a routine preoperative conference; the radiological diagnosis of nodal involvement was based on accepted morphologic criteria and FDG uptake. The primary tumors were located in the buccal mucosa (n = 4), upper gingiva (n = 11), lower gingiva (n = 12), hard palate (n = 3), tongue (n = 52), and floor of the mouth (n = 8). All patients were treated with local resection alone as primary treatment and watchful waiting for neck management. We reviewed DOI on pretreatment MRI and reclassified T stage according to the 8th edition AJCC. During the median follow-up period of 36 months (range, 2 - 122 months), the initial sites of recurrence were classified as local, nodal, and distant. Using Student's t-test and Pearson's chi-squared test, the MRI-derived DOI and T stage according to the 7th and 8th editions were assessed as predictive factors for nodal recurrence. The MRI-derived DOI was recorded as ≤ 5 mm in 42-, 5-10 mm in 37-, and > 10 mm in 11 patients. According to the 8th edition, 22 tumors were T1, 61 were T2, and 7 were T3 stage. During the follow-up period, 11 and 16 patients, respectively, suffered local and nodal recurrence; there were no patients with distant recurrence. The mean (± standard deviation) value of the MRI-derived DOI was significantly higher in the patients with nodal recurrence (8.4 ± 2.4 mm) than the others (4.7 ± 3.4 mm) (p < 0.001). The MRI-derived DOI classified significantly different risk groups for nodal recurrence; the incidence was 2% for tumor ≤ 5mm, 27% for 5-10 mm, and 46% for > 10 mm (p = 0.001). T stage according to the 8th edition also predicted the nodal recurrence; the incidence was 0% for T1, 21% for T2, and 43% for T3 stage (p = 0.016). However, T stage according to the 7th edition was not a significant factor for the nodal recurrence; no factors predicted the local recurrence. The MRI-derived DOI can predict nodal metastasis and the information may assist in treatment planning for oral SCC.

Multi-Institutional Evaluation of Curative Intent Chemoradiotherapy for Patients with Clinical T1N0 Esophageal Adenocarcinoma

To evaluate adverse events (AEs) and oncologic efficacy associated with curative-intent chemoradiotherapy (CRT) for patients with clinical T1N0 esophageal adenocarcinoma. This was a retrospective cohort study of patients with T1N0 adenocarcinoma of the esophagus treated with curative-intent CRT between 2004 and 2017 at two tertiary care centers. Toxicities were evaluated according to Common Terminology Criteria for AEs version 4.The Kaplan-Meier method was used to estimate overall (OS), progression-free (PFS), and disease-specific (DSS) survivals. A total of 28 patients were included for analysis. Patients did not undergo esophagectomy either due to medical comorbidity (54%) or patient preference (46%). The majority of patients were male (93%) and had a history of Barrett’s esophagus (71%). Median age was 76 (range 55-90), median Charlson Comorbidity Index was 1 (range 0-6), and baseline Eastern Cooperative Oncology Group performance status was 0 (57%) or 1-2 (43%). Tumor characteristics included distal esophagus location in 93%, clinical stage T1b in 86%, and median length of 2 cm (range 1-9). Tumor grade was 2 (54%) or 3 (46%). Treatment prior to CRT included endoscopic resection (ER) (57%) or induction chemotherapy (4%). Of those who underwent ER, 88% had a positive margin for invasive disease and 32% had pathologic evidence of lymphovascular invasion. Median RT dose was 50.4 Gy (range 40-50.4) in 28 fractions. RT techniques included 3D (32%), intensity modulated radiotherapy (43%), or proton therapy (25%). Concurrent chemotherapy was given to all patients, most commonly with 5-fluorouracil and taxane (43%) or platinum and taxane (29%) based regimens. Median follow-up was 44 months (range 4-146). Acute and late grade 3 gastrointestinal AEs were 18% and 7%, respectively. There were no grade 4 AEs. One patient died from treatment complications. Eight patients (29%) had disease progression at a median of 7.6 months after CRT. First site of progression was local in 4 (14%), local and regional in 3 (11%), or distant in 1 (4%). Salvage local treatment was performed in 3 patients, and included cryotherapy (n=1), ER + cryotherapy (n=1), or esophagectomy (n=1). The 3-year OS, PFS, and DSS were 78%, 62% and 81%, respectively. Tumor length > 2 cm was associated with worsened 3-year PFS (Hazard Ratio [HR]: 3.3, 95% confidence interval [CI]: 1.1-10.3) and 3-year DSS (HR 5.5, 95%CI: 1.04-29.4). Chemoradiotherapy is a safe and effective curative treatment strategy for select patients with clinical T1N0M0 esophageal adenocarcinoma.

Increasing omission of radiation therapy and sentinel node biopsy in elderly patients with early stage, hormone-positive breast cancer.

Prospective evidence demonstrates that there is limited benefit of axillary staging with sentinel lymph node biopsy (SLNB) or radiation therapy (RT) in patients over age 70 with clinical stage I, hormone-positive breast cancer. The clinical impact of this literature is unknown. Our hypothesis is that omission of SLNB and RT has increased over time in these patients, and patient and tumor characteristics can predict when omission strategies are used. A single-center tumor registry was queried for all patients over age 70 with ER+, Her2/neu-negative, clinical T1N0 invasive breast cancer from 2009 to 2017, who underwent breast conservation (n=141). Date of treatment, age, tumor characteristics, use of SLNB, and use of RT were evaluated. The trend of treatment strategy over time was evaluated. Multivariable analysis was performed on the subgroup of patients after publication of the long-term follow-up CALGB 9343 data1 . Patients undergoing treatment with omission of RT and SLNB increased over the study period (P=.0006). Patients who did not receive RT were older (78.76years±5.48 vs 73.37±3.63, P<.01). There was no difference between tumor grade and size between uses of RT. Of patients who received SLNB (n=84), only 3 (3.5%) had a positive LN. On multivariable analysis of patients who were treated after publication of the CALGB 9343 data (2014-2017), only age was predictive of being treated with RT (OR, 0.77; 95% CI, 0.67-0.88). Omission of both RT and SLNB are increasing in clinical practice in appropriately selected patients. The likelihood that patients are offered omission of these interventions increases with age. Low nodal positivity rates suggest that this strategy may be underutilized. Tumor grade and size were not predictive of omission of RT in this group of low-risk patients. Long-term data are needed as these approaches are increasingly adopted.

Survival Implications of Increased Utilization of Local Excision for cT1N0 Esophageal Cancer.

We hypothesized that patients with cT1N0 esophageal cancer undergoing local excision would have lower survival compared with esophagectomy due to potential discordant staging. Local excision has become an attractive alternative for management of early esophageal cancer, avoiding the morbidity of esophagectomy. It is uncertain if occult nodal metastasis impacts survival. An observational study was conducted using the National Cancer Database (1998-2012) for patients with clinical T1N0 esophageal cancer who underwent local excision (n = 1625) or esophagectomy (n = 3255). The proportion of patients undergoing local excision increased from 12% in 1998 to 50% in 2012 (P < 0.001). After esophagectomy, 61% of cT1N0 cancers had concordant clinical and pathological staging, with 5.2% having positive nodal disease; 37% were staged concordant after local excision, with excess missing data (60%). Ninety-day mortality was 7.4% after esophagectomy compared with 2.8% after local excision (P < 0.001). While no significant difference was seen in unadjusted survival, adjusted Cox regression analysis indicated worse survival after esophagectomy compared with local excision for all cases [hazard ratio (HR) 1.57, 95% confidence interval (CI) 1.27-1.95] and for patients with concordant staging (HR 1.68, 95% CI 1.23-2.28). Local excision for cT1N0 esophageal cancer has increased over time. Contrary to our hypothesis, despite incomplete nodal staging, patients undergoing local excision have favorable survival, particularly in the adenocarcinoma subgroup. This may reflect early differences in mortality due to differences in procedure-related complications and/or selection bias. As this study has limited power to compare outcomes between T1a and T1b cancers, further analysis is warranted.

Management of clinical T2N0 esophageal cancer: a review.

While management of locally advanced esophageal cancer has mostly involved multimodality therapy, management of clinical T2N0 patients has been more controversial, primarily as a result of inaccurate clinical staging with existing modalities. This review article examines current literature on this topic and provides recommendations for management of individual patients.

Health-related quality of life in patients with T1N0 oral squamous cell carcinoma: selective neck dissection compared with wait and watch surveillance

Management of the neck in patients with clinical T1N0 oral squamous cell carcinoma (SCC) is controversial. The aim of this study was to report the health-related quality of life (HRQoL) in a consecutive group of patients with stage 1 disease at a time closest to two years after primary surgery. Of 216 patients treated between 2007 and 2012 (after excluding early death and regional recurrence), 195 were eligible. HRQoL was measured using the University of Washington quality of life questionnaire version 4. The overall response rate was 65% (126/195). HRQoL outcomes were good, but compared with patients in the wait and watch group, those who had selective neck dissection (SND) had more problems regarding appearance (14% compared with 1%, p=0.008) and pain (19% compared with 6%, p=0.04). Similar trends were seen for shoulder (14% compared with 8%), mood (16% compared with 8%), and speech (5% compared with 1%), and for poorer overall QoL (30% compared with 16%). It is difficult to establish why patients did or did not have neck dissection in a retrospective sample, but it is likely that those who had SND had larger tumours. The findings highlight the impact that SND has on HRQoL in domains such as appearance, pain, speech, swallowing, and chewing. Previous studies on SND have tended to focus on injury to the accessory nerve and shoulder function, but these new data emphasise the need to include other domains in future trials that compare wait and watch, SND, and sentinel lymph node biopsy.

Prognosis of upstaged N1 and N2 disease after curative resection in patients with clinical N0 non-small cell lung cancer.

Nodal upstaging occasionally occurs after curative resection in clinical N0 non-small cell lung cancer (NSCLC). The purpose of this study was to evaluate the prognosis of clinical N0 NSCLC (T1-2, tumor size 5 cm or smaller) after upstaging to pathologic N1 or N2. From 2005 to 2015, 676 consecutive patients were diagnosed with clinical T1-2N0 NSCLC and underwent curative resection. Among these, tumors were upstaged to N1 in 46 patients and to N2 in 24 patients. We analyzed the prognosis of upstaged tumors. For comparison of prognosis between nodal upstaging groups and others in the same stage, patients with preoperative pathologically proven N1 (n=31) and N2 (n=55) NSCLC were included in the study. A total of 70 patients (10.4%) had nodal upstaging after curative resection of clinical N0 NSCLC. Upstaging to N1 occurred in 46 patients and upstaging to N2 occurred in 24 patients. The 5-year disease-specific survival rate was not statistically different between the upstaged and non-upstaged N1/N2 groups in N1 disease (73.3% vs. 70.5%, P=0.247) or in N2 disease (58.9% vs. 50.7%, P=0.283). Multivariate analysis showed that nodal upstaging was not a significant prognostic factor in N1 or N2 NSCLC (hazard ratio =0.385, P=0.235; hazard ratio =0.677, P=0.458). Postoperative nodal upstaging from clinical T1-2N0 NSCLC was not a significant prognostic factor in the same stage. Therefore, surgical treatment of clinical T1-2N0 lung cancer diagnosed by imaging without preoperative pathologic lymph node staging can be a treatment option.

Multidisciplinary Therapy of Esophageal Cancer.

Multimodality therapy is the standard of care for locoregional esophageal cancers (greater than clinical T3 or Nþ), including Siewert type 1 and 2 gastroesophageal junction tumors. Induction regimen, chemotherapy only or chemoradiation, is an area of controversy and often institution-specific, as neither has shown to be superior. Response to induction therapy is an important prognostic marker. For esophageal squamous cell carcinoma, it may be acceptable to observe clinical complete responders after chemoradiotherapy and perform salvage esophagectomy for recurrent disease. Clinical T2N0 esophageal cancer presents a unique challenge given its inaccuracy in clinical staging; management of this particular subset is controversial.

Nutritional safety of oncometabolic surgery for early gastric cancer patients: a prospective single-arm pilot study using a historical control group for comparison.

Oncometabolic surgery (OS) is a modification of the Roux-en Y reconstruction method, in which the lengths of the biliopancreatic and Roux limbs are longer than that with conventional surgery (CS). Although OS is performed to improve postoperative glycemic control in gastric cancer patients with type 2 diabetes mellitus (T2DM), its postoperative nutritional safety has not been clarified. This prospective pilot study evaluated the safety and feasibility of OS in early gastric cancer patients. This study evaluated 20 patients with clinical T1N0 stage and preoperative body mass index (BMI) ≥ 32.5kg/m2, or ≥ 27.5kg/m2 with comorbidities, who underwent OS. Primary outcomes were cumulative incidences of anemia and deficiencies in iron and vitamin B12 after 1year. The outcomes were compared to those of a matched historical control group. The cumulative incidences of anemia (15.0% vs. 10.0%, P = 0.99), iron deficiency (15.0% vs. 10.0%, P = 0.99), and vitamin B12 deficiency (10.0% vs. 0%, P = 0.47) did not differ significantly in the OS and CS groups. However, median vitamin B12 concentration tended to be lower (395.8 vs. 493.7pg/mL, P = 0.06) and reductions in vitamin B12 concentration tended to be greater (174.7 vs. 123.0pg/mL, P = 0.07) in the OS group. BMI loss was similar in the two groups (2.9 vs. 2.8kg/m2, P = 0.80). Remission rates of hypertension (68.8% vs. 41.2%, P = 0.22) and T2DM (77.8% vs. 50.0%, P = 0.58) were higher in the OS group. Nutritional parameters did not differ significantly in the OS and CS groups. Vitamin B12 levels should be carefully monitored after OS.

Machine learning to predict occult nodal metastasis in early oral squamous cell carcinoma

ObjectivesTo develop and validate an algorithm to predict occult nodal metastasis in clinically node negative oral cavity squamous cell carcinoma (OCSCC) using machine learning. To compare algorithm performance to a model based on tumor depth of invasion (DOI). Materials and methodsPatients who underwent primary tumor extirpation and elective neck dissection from 2007 to 2013 for clinical T1-2N0 OCSCC were identified from the National Cancer Database (NCDB). Multiple machine learning algorithms were developed to predict pathologic nodal metastasis using clinicopathologic data from 782 patients.The algorithm was internally validated using test data from 654 patients in NCDB and was then externally validated using data from 71 patients treated at a single academic institution. Performance was measured using area under the receiver operating characteristic (ROC) curve (AUC). Machine learning and DOI model performance were compared using Delong’s test for two correlated ROC curves. ResultsThe best classification performance was achieved with a decision forest algorithm (AUC = 0.840). When applied to the single-institution data, the predictive performance of machine learning exceeded that of the DOI model (AUC = 0.657, p = 0.007). Compared to the DOI model, machine learning reduced the number of neck dissections recommended while simultaneously improving sensitivity and specificity. ConclusionMachine learning improves prediction of pathologic nodal metastasis in patients with clinical T1-2N0 OCSCC compared to methods based on DOI. Improved predictive algorithms are needed to ensure that patients with occult nodal disease are adequately treated while avoiding the cost and morbidity of neck dissection in patients without pathologic nodal disease.

Topographical distribution of sentinel nodes and metastases from T1–T2 oral squamous cell carcinomas

ObjectiveThe objective is to investigate the topographical distribution of sentinel nodes (SNs) and lymph node metastases in T1-2cN0 oral squamous cell carcinomas (OSCCs). MethodsThe study entailed a prospective enrolment of 220 patients with clinical T1-2N0 OSCCs who underwent preoperative lymphoscintigraphy (LSG) followed by gamma probe–guided sentinel lymph node biopsy (SLNB). Patients with positive SNs were treated with completion neck dissection. Excised lymph nodes were grouped into the neck level according to the international guidelines. ResultsThe SN detection rate by LSG was 99.1%. Patients with midline tumours had bilateral lymphatic drainage on LSG in 15/21 (71.5%). There were 45/199 (22.6%) patients with lateralised tumours that had unexpected bilateral or contralateral drainage patterns on LSG. Fifty-five patients (25.0%) were SLNB positive, and metastases were found in 72/781 (9.2%) of the excised SNs. Metastatic involvement of neck level IV was rare and only observed in patients with anterior tongue cancer. No patients had level V involvement. Eleven patients developed isolated cervical recurrences, with no new primary tumour as origin. The SLNB procedure ensured an overall sensitivity of 83.3% and a negative predictive value of 93.3%. ConclusionCompletion neck dissection of level I–III in SLNB-positive patients might be sufficient in most patients with OSCC except patients with anterior tongue cancer, but further studies are needed to support this potential therapeutic algorithm. Our study showed that SLNB was helpful in clarifying unexpected bilateral or contralateral metastatic drainage patterns. In our cohort, 8/55 patients with occult metastasis would have been missed by elective neck dissection of the ipsilateral neck.

Management for Pathologic N1-N2 Disease after Definitive Surgery for Clinical T1-2 N0 Rectal Cancer

Management for Pathologic N1-N2 Disease after Definitive Surgery for Clinical T1-2 N0 Rectal Cancer

MS27.01 Staging of Lymph Nodes in Early Stage NSCLC: Therapeutic Implications

MS27.01 Staging of Lymph Nodes in Early Stage NSCLC: Therapeutic Implications

Reliability of MRI-Derived Depth of Invasion of Oral Tongue Cancer

To evaluate the inter-rater reliability of the magnetic resonance imaging (MRI)-derived depth of invasion (DOI) and the agreement between MRI and pathological measurements of oral tongue cancer. The institutional review board approved this retrospective study. The study population consisted of 29 patients with clinical T2N0 oral tongue cancer treated by surgery. Routine pretreatment MRI was performed on a 3T superconducting imager. Two raters with 23 and 18 years of head-and-neck MRI experience, respectively, independently chosen MRI sequences for each patient, then delineate the tumor, and then used three protocols to measure the MRI-derived DOI: the axial reconstructed thickness (method 1), the axial invasive portion (method 2), and the coronal invasive portion (method 3). Then they consensually selected the optimal among the three methods for each patient; it was designated method 4. The Bland-Altman plots, intraclass correlation coefficients (ICCs), and the paired samples test were used. According to the median follow-up of 41 months, the relationship between the MRI-derived DOI and nodal recurrence was also investigated. The inter-rater reliability of methods 2 and 4 was excellent (ICC of 0.829 and 0.807, respectively). The correlation between MRI and pathological measurements was good for method 4 (ICC of 0.611), however, all measurements recorded on MRI were 2-3 mm larger than on pathology. No patients whose MRI-derived DOI was less than 5 mm suffered nodal recurrence. The MRI-derived DOI was valuable for the preoperative staging. The optimal measurement method should be selected on a case-by-case basis.

PS01.134: WHERE TO START? COMPARING INDUCTION CHEMORADIOTHERAPY AND UPFRONT SURGERY IN THE TREATMENT OF CLINICAL T2N0 ESOPHAGEAL CANCER

Abstract Background The purpose of this study was to evaluate the survival difference in clinical T2N0 esophageal cancer patients receiving neoadjuvant chemoradiotherapy (CRT) vs. upfront surgery. Methods Between 1/1/1995 to 12/31/2012, a prospectively maintained database was used to identify patients with cT2N0 esophageal adeno- and squamous cell carcinoma. Exclusion criteria included: lack of endoscopic esophageal ultrasonographic (EUS) staging, incomplete resection, and prior treatment with endoscopic mucosal or submucosal resection. Cox-proportional hazard ratios were used to compare the primary outcomes of overall (OS) and disease-free survival (DFS). Secondary outcomes included: rate of postoperative complications, rate of pathologic upstaging/response, and induction/adjuvant treatment completion rate. Pre-hoc subgroup analysis compared pathologically upstaged patients receiving upfront surgery followed by adjuvant chemotherapy to those treated with neoadjuvant CRT. Results A total of 161 cT2N0 esophageal cancer patients were identified based on EUS staging. Upfront surgery was offered to 134 patients (83%), with 27 patients (17%) receiving induction CRT. Univariate analysis did not demonstrate any significant baseline differences between the two groups. In the upfront surgery group, 53 (39.6%), 28 (20.9%) and 53 (39.6%) patients were pathologically down-staged, accurately staged and upstaged respectively. Upstaging was higher in the upfront surgery group (53/134, 39.6% vs. 4/27, 14.8%; P = 0.02), while 11/27 (40.7%) patients receiving neoadjuvant CRT demonstrated complete pathologic response. Of those eligible for adjuvant chemotherapy, only 21/55 (38.2%) received treatment. In the neoadjuvant CRT group, 51.9% completed all planned therapy, compared to 23.6% of patients treated with upfront surgery followed by adjuvant chemotherapy (P = 0.01). Cox proportional hazard ratio did not demonstrate an advantage to induction CRT in terms of OS (HR = 1.64, P = 0.43) or DFS (HR = 1.36, P = 0.69). In general, patients with pathologic upstaging had worse OS (HR = 2.73, P = 0.001) and DFS (HR = 4.18, P = 0.003). Conclusion EUS was only accurate in staging T2N0 patients in 20.9% of cases. While neoadjuvant CRT did not confer a survival advantage, these results likely reflect the low number of patients being referred for induction therapy. Neoadjuvant CRT was however associated with lower rates of pathologic upstaging and higher rates of treatment completion. Further research should evaluate the survival outcomes in pathologically upstaged cT2N0 patients not receiving neoadjuvant therapy. Disclosure All authors have declared no conflicts of interest.

Intrafraction esophageal motion in patients with clinical T1N0 esophageal cancer.

To investigate the intrafraction movement of the esophagus using fiducial markers. Studies on intrafraction esophageal motion using the fiducial markers are scarce. We retrospectively analyzed patients with clinical T1N0 esophageal cancer who had received fiducial markers at our hospital between July 2007 and December 2013. Real-Time Position Management System to track the patient's respiration was used, and each patient underwent three-dimensional computed tomography of the resting expiratory and inspiratory level. We used the center of the marker to calculate the distance between the expiratory and inspiratory breath-holds, which were measured with the radiotherapy treatment planning system in three directions: left-right (LR), superior-inferior (SI), and anterior-posterior (AP). The movements at each site were compared with the Kruskal-Wallis analysis and Wilcoxon rank sum test with a Bonferroni correction. A total of 101 patients with 201 fiducial markers were included. The upper, middle and lower thoracic positions had 40, 77, and 84 markers, respectively. The mean absolute magnitudes of the shifts (standard deviation) were 0.18 (0.19) cm, 0.68 (0.46) cm, and 0.24 (0.24) cm in the LR, SI, and AP directions, respectively. From the cumulative frequency distribution, we assumed that 0.35 cm LR, 0.8 cm SI, and 0.3 cm AP in the upper; 0.5 cm LR, 1.55 cm SI, and 0.55 cm AP in the middle; and 0.75 cm LR, 1.9 cm SI, and 0.95 cm AP in the lower thoracic esophagus covered 95% of the cases. The internal margin based on the site of esophagus was estimated.

The Potential Impact of AMAROS on the Management of the Axilla in Patients with Clinical T1-2N0 Breast Cancer Undergoing Primary Total Mastectomy.

Recent trials have demonstrated that axillary observation or axillary radiation therapy (AxRT) is equivalent to axillary node dissection (ALND) for patients with one or two positive sentinel lymph nodes (SLNs). These strategies have been widely adopted for patients having breast conservation. This report demonstrates the potential impact of the AMAROS trial on axillary therapy in a retrospective cohort of mastectomy patients. Patients undergoing primary mastectomy for cT1-2N0 breast cancer who had one or two positive SLNs were identified from institutional databases (2005-2015). Locoregional management strategies were evaluated, and variables predictive of the use of postmastectomy radiation therapy (PMRT) were identified. Among 2594 mastectomies, 193 (7%) met the AMAROS eligibility criteria. The median patient age was 50years (range 22-83years). Locoregional treatment consisted of ALND + PMRT for 102 patients (53%), ALND alone for 66 patients (34%), PMRT alone for 11 patients (6%), and observation for 14 patients (7%). Overall, 59 ALND patients (35%) had additional positive nodes. In the multivariate analysis, age younger than 50years (odds ratio [OR] 3.55; 95% confidence interval [CI] 1.57-8.45), lymphovascular invasion (LVI) (OR 5.78; 95% CI 2.53-4.78), macrometastases (OR 3.99; 95% CI 1.54-10.97), and extracapsular extension (OR 11.66; 95% CI 2.55-88.34) were associated with receipt of PMRT. In this cohort of AMAROS-eligible patients, 168 (87%) underwent ALND, 102 (61%) of whom also received PMRT, suggesting that AxRT could have been used instead of ALND for a significant number of patients. Preoperative factors associated with the receipt of PMRT, such as young age and LVI, may be useful for defining a multidisciplinary decision-making framework for axillary management in this population.