Yoshikazu Miyasaka

The maximum standardized uptake value of fluorodeoxyglucose positron emission tomography of the primary tumour is a good predictor of pathological nodal involvement in clinical N0 non-small-cell lung cancer

OBJECTIVES Fluorodeoxyglucose positron emission tomography (FDG-PET) plays an important role in the evaluation of resectable non-small-cell lung cancer (NSCLC). However, this modality cannot be used to detect histological nodal involvement, which can result in stage-migration for resectable lung cancer. In this study, we tried to evaluate the possibility of predicting histological nodal involvement in patients with NSCLC using the maximum standardized uptake value (SUVmax) of FDG-PET of the primary tumour instead of that of the lymph nodes. METHODS Between February 2008 and September 2011, 898 patients underwent lung cancer surgery at our institute. Among them, we retrospectively analysed 265 patients with clinical N0 NSCLC, who underwent preoperative FDG-PET. The relationships between clinicopathological features, including the findings of FDG-PET and pathological nodal involvement, were investigated. The factors investigated were age, gender, preoperative carcinoembryonic antigen titre, maximum tumour dimension, consolidation/tumour dimension ratio (C/T ratio), SUVmax in the primary tumour and smoking history. RESULTS Of the 265 clinical N0 NSCLC patients, 214 (80.8%) had pathological N0 status and 27 (10.2%) and 24 (9.0%) had pathological N1 and N2 disease. In a multivariate analysis, the C/T ratio (P = 0.046) and SUVmax of the primary tumour (P = 0.016) were significant predictors of pathological nodal involvement. With regard to pathological N1-2 disease, the sensitivity, specificity, accuracy and positive and negative predictive values of mediastinal node involvement in patients with NSCLC with an SUVmax for FDG-PET of 10 or more were 49.0, 83.2, 76.6, 41.0 and 87.3%, respectively. Of the 61 patients with NSCLC with an SUVmax for FDG-PET of 10 or more, 25 (41.0%) had pathological N1-2 disease, while only 26 (12.7%) of the remaining 204 patients with an SUVmax for FDG-PET of <10 had nodal disease (P < 0.0001). CONCLUSIONS Postoperative nodal status was significantly predicted by the SUVmax of FDG-PET of the primary tumour instead of the lymph nodes themselves. The patients with NSCLC in particular who show strong uptake values of SUVmax in the primary tumour could have occult nodal metastases, and may be indicated for a further preoperative modality for an accurate staging.

What is the appropriate operative strategy for radiologically solid tumours in subcentimetre lung cancer patients

OBJECTIVES Solid lung cancers, even subcentimetre lesions, are considered to be invasive pathologically. However, the clinicopathological features and appropriate operative strategies in patients with these small lesions are still controversial, especially for those with a radiologically solid appearance. METHODS Between 2004 and 2011, 135 patients underwent pulmonary resection for subcentimetre lung cancer with clinical-N0 (c-N0) status. The findings of preoperative thin-section computed tomography (CT) were reviewed, and subcentimetre lung cancer was divided into three groups: pure ground-glass nodule, part-solid and pure-solid lesions. RESULTS Among the 135 subcentimetre lung cancer patients with c-N0 status, 71 showed a solid appearance on thin-section CT scan. Furthermore, pathological nodal examinations were performed in 49 patients, and nodal involvement was found pathologically in 6 (12.2%) patients. All of them had pure-solid tumours (P = 0.0010). Among the patients with solid subcentimetre lung cancers, the maximum standardized uptake value (SUVmax) was the only significant predictor of nodal involvement by a multivariate analysis (P = 0.0205). With regard to the surgical outcomes, the overall 5-year survival and disease-free survival rates were 100 and 97.8% for part-solid lesions, and 87.3 and 74.8% for pure-solid lesions, respectively. Moreover, there was a significant difference in disease-free survival between a high SUVmax group (60.0%) and a low SUVmax group (94.9%) (P = 0.0013). CONCLUSIONS There might be a possibility of lymph node metastasis despite subcentimetre lung cancer, especially for radiological pure-solid nodules that show a high SUVmax. If limited surgery is indicated for solid subcentimetre lung cancer, a thorough intraoperative evaluation of lymph nodes is needed to prevent loco-regional failure.

Use of silicone gel sheets for prevention of keloid scars after median sternotomy

PurposeA keloid scar often appears at the incision site of patients after median sternotomy. Use of silicone gel to treat hypertrophic burn scars and fresh incisions has yielded encouraging results. In this study, we report our experience with the preventive use of silicone gel sheets for keloid scars after median sternotomy.MethodsNine patients who underwent a median sternotomy were studied. A silicone gel sheet was kept directly on the surgical incision for 24 h starting 2 weeks after surgery. The treatment was repeated with a new sheet every 4 weeks for 24 weeks, at which times the subjective symptoms and the changes in keloid scars were determined.ResultsNone of the patients experienced an aggravation of any subjective symptoms during the 24-week study. After 24 weeks, all patients were free of a keloid scar that showed a rise and contraction of skin and causes discomfort. No adverse events were reported by any of the patients.ConclusionA silicone gel sheet is safe and effective for the preventing the formation of keloid scars after median sternotomy.

Postoperative complications and respiratory function following segmentectomy of the lung - comparison of the methods of making an inter-segmental plane.

Segmentectomy could be one of the standard modes of surgery for the treatment of early lung cancer. However, segmentectomy could be more difficult than lobectomy as to the management of inter-segmental plane. The relationship between methods of dividing an inter-segmental plane and postoperative complication/pulmonary function was investigated in this study. A retrospective study was conducted on 49 patients who underwent segmentectomy of the lung between February 2008 and April 2009 at our institute. Eighteen (36.7%) were male and 31 (63.3%) were female. The inter-segmental plane was divided with only a mechanical stapler in 18 patients, and electrocautery was used in the other 31 patients. There were no significant relationships between clinicopathological features and both procedures, except gender, operative time, and pleurodesis (P<0.05). Preserved forced expiratory volume in one second (FEV(1)) was not affected by the procedures. Patients who underwent left upper division segmentectomy had significantly more complications. On multivariate analysis, resected segment and intraoperative blood loss were found to be significant predictors for postoperative complications. There were no significant relationships between the methods of making inter-segmental planes and postoperative complications and/or lung functions. Resected segment and intraoperative blood loss were predictors for postoperative complication in segmental resection of the lung.

New technique for lung segmentectomy using indocyanine green injection.

One of the most difficult aspects of complete segmentectomy of the lung is the identification of the intersegmental plane. Instead of a conventional residual segment inflation method, we have developed a new technique for detecting intersegmental planes using indocyanine green medium. The technique is simple and consists of (1) ligation of the segmental vein to prevent loss of the indocyanine green and (2) injection of indocyanine green through the segmental bronchus. These two steps result in easy identification of intersegmental planes by a change of color not only of the surface but also of the parenchyma of the lung. This technique can be indicated for atypical segmentectomy.

Lung cancer with scattered consolidation: detection of new independent radiological category of peripheral lung cancer on thin-section computed tomography

OBJECTIVES Ground glass opacity (GGO) on thin-section computed tomography (CT) has been reported to be a favourable prognostic marker in lung cancer, and the size or area of GGO is commonly used for preoperative evaluation. However, it can sometimes be difficult to evaluate the status of GGO. METHODS A retrospective study was conducted on 572 consecutive patients with resected lung cancer of clinical stage IA between 2004 and 2011. All patients underwent preoperative CT and their radiological findings were reviewed. The areas of consolidation and GGO were evaluated for all lung cancers. Lung cancers were divided into three categories on the basis of the status of GGO: GGO, part solid and pure solid. Lung cancers in which it was difficult to measure GGO were selected and their clinicopathological features were investigated. RESULTS Seventy-one (12.4%) patients had lung cancer in whom it was difficult to measure GGO. In all these cases, consolidation and GGO were not easily measured because of their scattered distribution. In this cohort, nodal metastases were not observed at all. The frequency of other pathological factors, such as lymphatic and/or vascular invasion, was significantly lower (P < 0.0001). CONCLUSIONS This new category of lung cancer with scattered consolidation on thin-section CT scan tended to be pathologically less invasive. When lung cancer has GGO and is difficult to measure because of a scattered distribution, its prognosis could be favourable regardless of the area of GGO. This new category could be useful for the preoperative evaluation of lung cancer.

The Impact of Cigarette Smoking on Prognosis in Small Adenocarcinomas of the Lung: The Association Between Histologic Subtype and Smoking Status

Objective: In this retrospective study, we clarified the impact of smoking on prognosis and the association of clinicopathological factors, particularly histologic subtype, in patients with small adenocarcinoma of the lung. Methods: Between 1996 and December 2006, 121 patients presenting with adenocarcinomas that had a diameter ≤2 cm were analyzed. The clinicopathological records of the patients were examined for age, gender, nodal status (c-N and p-N), tumor size, serum carcinoembryonic antigen level, histologic subtype, and smoking history. A histologic subtype was defined using a modified World Health Organization classification. These subtypes are bronchioloalveolar carcinoma (BAC), adenocarcinoma with little or no BAC component (Non or min BAC), and mixed bronchioloalveolar carcinoma with other adenocarcinoma components. Results: The overall 5-year survival rates were 94.4% for never-smokers (N = 55) and 79.2% for smokers (N = 66) (p = 0.05). Cancer-specific 5-year survival rates were 98.0% for never-smokers and 80.4% for smokers (p = 0.03). Gender, serum carcinoembryonic antigen level, and histologic subtype were significantly associated with smoking status. Histologic subtype (Non or min BAC) was the only significant prognostic factor in multivariate analyses. The prevalence of smoking by histologic subtype was 27.3% for BAC, 43.2% for mixed bronchioloalveolar carcinoma, and 74.6% for Non or min BAC. The prevalence was significantly higher in Non or min BAC than in the others. Furthermore, the smoking index (daily cigarette consumption times years of smoking) was significantly higher in Non or min BAC than in the other two subtypes. In addition, patients with a high smoking index showed a greater percentage of Non or min BAC subtypes. Finally, male gender was associated with Non or min BAC independent of smoking status (p = 0.03). Conclusions: When adenocarcinomas were small (diameter ≤2 cm) cigarette smoking and male gender were associated with Non or min BAC histologic subtypes, which are thought to have more aggressive biologic features resulting in poorer outcome compared with other subtypes.

Experience of silicone gel sheets for patients with keloid scars after median sternotomy

PurposeIt is often difficult to control hypertrophic scars and keloids with drug therapy, steroid injection, surgery, radiation therapy, laser, or wound pressing. Use of silicone gel to treat hypertrophic burn scars and fresh incisions has yielded encouraging results. We report our experience of silicone gel sheets for patients with keloids following median sternotomy.MethodsNine patients underwent a median sternotomy and received other therapies before participating in this treatment. A silicone gel sheet was placed directly on the keloid scar and maintained at all times. Sheets were replaced every 4 weeks for a total treatment duration of 24 weeks. The scar area was measured, and subjective symptoms were determined prior to therapy and after completion of therapy.ResultsThere were three men and six women, with a mean age of 45.2 years (range 22–69 years). Progression of protuberance and rub was seen in one patient. Scar redness and cramping were either diminished or unchanged in all patients. Itching progressed in two patients. After 6 months, the area of the scar relative to its initial area was 0.98 (range 0.78–1.27). Harmful events did not occur.ConclusionA silicone gel sheet is effective for treating keloid scars following median sternotomy. Silicone gel sheets are safe and easy to use and do not aggravate any subjective symptoms.

The presence of air bronchogram is a novel predictor of negative nodal involvement in radiologically pure-solid lung cancer.

OBJECTIVES Phase III trials regarding the feasibility of segmentectomy for lung cancer ≤ 2 cm in size are now underway in Japan and the USA. However, despite their small size, lung cancers that show a pure-solid appearance on thin-section computed tomography (CT) are considered to be invasive with a high frequency of nodal involvement. METHODS Between 2008 and 2011, 556 clinical Stage IA lung cancer patients underwent pulmonary resection. For all patients, the findings obtained by preoperative thin-section CT were reviewed and the maximum standardized uptake value (SUVmax) on positron emission tomography was recorded. Several clinicopathological features were investigated to identify predictors of nodal metastasis using multivariate analyses. RESULTS One hundred and eighty-four clinical Stage IA lung cancer patients showed a pure-solid appearance on thin-section CT. Among them, air bronchogram was found radiologically in 58 (32%) patients. Nodal involvement was observed in 10 (17%) patients with air bronchogram, compared with 43 (34%) without air bronchogram, in clinical Stage IA pure-solid lung cancer. A multivariate analysis revealed that air bronchogram, clinical T1a and SUVmax were significant predictors of postoperative nodal involvement (P < 0.01, <0.01, and 0.03, respectively). Furthermore, nodal metastasis was never seen in patients with clinical T1a pure-solid lung cancers who had both air bronchogram and low SUVmax. CONCLUSIONS The presence of air bronchogram was a novel predictor of negative nodal involvement in clinical Stage IA pure-solid lung cancer. Segmentectomy with thorough lymph node dissection is a feasible option for these patients despite a pure-solid appearance.

Prospective randomized trial comparing buttressed versus nonbuttressed stapling in patients undergoing pulmonary lobectomy.

BACKGROUND The aim of this study was to evaluate the efficacy of buttressed stapling using a stapler with an attached polyglycolic acid sheet in reducing the rate of air leak associated with pulmonary lobectomy. Materials and METHODS A prospective, randomized, phase III study was conducted to confirm the superiority of a buttressed stapler in a test treatment group to a conventional nonbuttressed stapler in a current international standard of care group among patients undergoing pulmonary lobectomy. The primary end point was the frequency of intraoperative air leaks. RESULTS Although no fatal postoperative bleeding occurred in the present study, this trial closed early with 100 patients because the manufacturer recalled the buttressed stapler based on reports of 13 serious injuries and 3 fatalities following pulmonary resection in routine clinical practice. A total of 76 patients treated with a stapler (35 in the non-B group and 41 in the B group) were included as subjects in the analysis. No statistical differences were observed between the groups in the frequency of intraoperative air leaks (22 [63%] vs. 26 [63%]) or the postoperative duration of air leaks (mean: 3.5 vs. 2.9 days). The frequency of air leak from stapler holes was significantly lower in the B group than in the non-B group (2% [1/41] vs. 20% [7/35]; p=0.016). CONCLUSIONS The efficacy of buttressed stapling in reducing the rate of air leak in patients undergoing pulmonary lobectomy could not be clearly demonstrated. However, air leak from stapler holes can be prevented with buttressed stapling.