a cancer board ( cb ) is a multidisciplinary cancer conference to discuss the best treatments for cases , according to the opinions of healthcare professionals from various specialties ( physicians , surgeons , medical oncologists , radiation oncologists , diagnostic radiologists , palliative care specialists , pathologists , nurses , and pharmacists ) ( 1,2 ) . the multidisciplinary approach of the cb has drawn attention in the field of cancer treatment , because of the growing specialization and complexity of medical practice . in the united kingdom , more than 80% of treatments for newly diagnosed cancer patients have been discussed in a cb ( 3 ) . the effect of cbs on the treatment decisions and outcomes has been reported ( 4 - 9 ) , along with other additional benefits related to education , learning , or research ( 10,11 ) , thus making their value widely recognized . medical oncologists act not only as professionals of chemotherapy , but also as coordinators of multidisciplinary cancer treatment ( 12 ) , and their role is widely recognized in western countries ; there are approximately 15,000 medical oncologists in the united states ( approximate population : 320 million ) . in contrast , a total of only 954 medical oncologists were certified by the japanese society of medical oncology by the year 2014 ( approximate population in japan : 130 million ) ( 13 ) , although their role has started to be recognized over the past decade ( 14 ) . facilitators  or  conductors  in cbs ( 10,11 ) , and with the increase of medical oncologists in japan , cbs are now becoming common in japan . cbs are held on a regular basis in designated cancer hospitals and many other hospitals in japan ( 15 ) . however , only a limited knowledge exists about the influence of cancer boards with respect to treatment decisions regarding chemotherapy , especially in asian regions . in order to address these gaps in the literature , we assessed the effect of cbs on the treatment decisions regarding chemotherapy by investigating cases of cbs during which chemotherapy was discussed , at yamagata university hospital . yamagata university hospital is a designated cancer care hospital in yamagata prefecture , located about 300 km north of tokyo , japan . details of our hospital and the cbs are described elsewhere ( 2,16 ) . in brief , cbs are held every tuesday and biweekly on wednesdays ( separated into 13 boards according to the type of cancer ) , and focus on the best treatment for each case . the timetable for the boards medical oncologists , radiation oncologists , diagnostic radiologists , palliative care specialists , physicians and surgeons from each specialty , and any other personnel who ought to participate in the discussion ( e.g. pathologists , nurses , pharmacists , and medical students ) attended the cb , to form a multidisciplinary cancer conference . separated into a gastrointestinal board and hepatobiliopancreatic board .  cancers of the central nervous system . we collected data from cbs and clinical records to analyze the details of the discussions and the chosen plan of treatment . we counted the number of cases discussed at cbs ; thus , the same patient could be counted more than once , according to the number of times the case was presented at the cb . however , the number of patients was counted , not cases , when assessing the number of patients who were referred to the medical oncologist in addition to the cb . the details of the discussions and the chosen plan of treatment were classified into six categories ( a to f ) . other ,  when more detailed examination was needed , more detailed survey of publications was needed , or the treatment choice was to be made by the patient . classification of determinations at cancer boards .   regardless of whether chemotherapy was involved or not . cases in which chemotherapy was not mentioned in the discussion are classified into this category . 
  a difference in the proportions of the categories of determination for cases introduced to medical oncologists versus those who were not were compared using pearson 's chi - square test with yate 's continuity correction , post - hoc mcnemar 's chi - square test with continuity correction , and the bonferroni - holm adjustment for multiple comparisons . fisher 's exact test was performed instead , when any of the categories ' expected values were below 5 . a p value < 0.05 was considered to be statistically significant . statistical analyses were performed using the r software version 3.0.2 ( r foundation for statistical computing , vienna , austria ) . yamagata university hospital is a designated cancer care hospital in yamagata prefecture , located about 300 km north of tokyo , japan . details of our hospital and the cbs are described elsewhere ( 2,16 ) . in brief , cbs are held every tuesday and biweekly on wednesdays ( separated into 13 boards according to the type of cancer ) , and focus on the best treatment for each case . the timetable for the boards medical oncologists , radiation oncologists , diagnostic radiologists , palliative care specialists , physicians and surgeons from each specialty , and any other personnel who ought to participate in the discussion ( e.g. pathologists , nurses , pharmacists , and medical students ) attended the cb , to form a multidisciplinary cancer conference . separated into a gastrointestinal board and hepatobiliopancreatic board .  cancers of the central nervous system . we collected data from cbs and clinical records to analyze the details of the discussions and the chosen plan of treatment . we counted the number of cases discussed at cbs ; thus , the same patient could be counted more than once , according to the number of times the case was presented at the cb . however , the number of patients was counted , not cases , when assessing the number of patients who were referred to the medical oncologist in addition to the cb . the details of the discussions and the chosen plan of treatment were classified into six categories ( a to f ) . other ,  when more detailed examination was needed , more detailed survey of publications was needed , or the treatment choice was to be made by the patient . classification of determinations at cancer boards .   regardless of whether chemotherapy was involved or not . cases in which chemotherapy was not mentioned in the discussion are classified into this category . 
  a difference in the proportions of the categories of determination for cases introduced to medical oncologists versus those who were not were compared using pearson 's chi - square test with yate 's continuity correction , post - hoc mcnemar 's chi - square test with continuity correction , and the bonferroni - holm adjustment for multiple comparisons . fisher 's exact test was performed instead , when any of the categories ' expected values were below 5 . a p value < 0.05 was considered to be statistically significant . statistical analyses were performed using the r software version 3.0.2 ( r foundation for statistical computing , vienna , austria ) . overall , 7,489 patients were registered in the institutional cancer registry during the same period ; thus , approximately 20.6% ( 1,541/7,489 ) of the cases at our hospital were discussed at the cb . the number of cases discussed at each board and the determinations are shown in table 3 . among 811 cases [ 811/1,541 ( 52.6% ) ] that involved discussions concerning chemotherapy , treatment alterations the lung board had the largest number of cases ( n=296 ) , followed by hematology ( n=245 ) , and urology ( n=244 ) . in terms of cases in which chemotherapy was involved , the lung board also had the largest number ( n=185 ) , followed by hematology ( n=171 ) , and gastrointestinal ( n=110 ) . alteration of the chemotherapy plan was observed in 189/1,541 ( 12.3% ) of all cases , and 189/811 ( 23.3% ) of cases in which chemotherapy was involved ( table 3 ) . alteration of the planned treatment showed the largest proportion in the  other  category [ 5/10 ( 55.6% ) ] , followed by bone and soft tissue [ 12/27 ( 44.4% ) ] , breast [ 4/11 ( 36.4% ) ] , gastrointestinal [ 39/110 ( 35.5% ) ] , and hepatobiliopancreatic [ 6/17 ( 35.3% ) ] . an excessively small proportion compared to other boards was seen for the hematology board [ cases with altered chemotherapy plans : 5/171 ( 2.9% ) ] and pediatric board [ 0/10 ( 0.0% ) ] . treatment regarding chemotherapy was not planned ( e.g. , neo - adjuvant or adjuvant chemotherapy ) in most cases that were classified as category c ( 63/66 ) ; however , in three cases , a decision was made not to administer chemotherapy . the reasons for discouraging chemotherapy varied ; however , 29/45 ( 64.4% ) cases were classified as category d for the following reasons : old age , comorbid condition , physical ( performance ) status , or insufficient evidence to administer chemotherapy . a : chemotherapy not discussed ; b : approval of planned chemotherapy ; c : recommendation of unplanned chemotherapy ; d : discouragement of planned chemotherapy ; e : alteration of treatment sequence and/or chemotherapy regimen ; f : other . details within each board are as follows : brain 13/170 ( 7.6% ) , bone and soft tissue 12/72 ( 16.7% ) , breast 4/13 ( 30.8% ) , gastrointestinal 39/147 ( 26.5% ) , gynecology 22/97 ( 22.7% ) , head and neck 23/148 ( 15.5% ) , hematology 5/245 ( 2.0% ) , hepatobiliopancreatic 6/56 ( 10.7% ) , lung 51/296 ( 17.2% ) , others 5/27 ( 18.5% ) , pediatric 0/25 ( 0% ) , and urology 14/244 ( 5.7% ) . overall , 93 patients were treated in the medical oncology department , and 86 patients were referred through the cbs ( table 4 ) . category a included cases in which chemotherapy was administered , but they were not mentioned in the discussion at cbs ; 13 patients were classified in this category . of these , seven cases were presented only to discuss radiotherapy , and chemoradiotherapy was performed in the clinical oncology department . the other six cases were referred to the medical oncologist as outpatients afterwards , without chemotherapy being discussed at the cb , in order to provide information about chemotherapy to the patient according to their request . seven patients were referred to the medical oncologist before being presented at the cb , and thus were excluded from the number referred through the cbs . number of patients discussed at cancer boards who were treated in the medical oncology department . a : chemotherapy not discussed ; b : approval of planned chemotherapy ; c : recommendation of unplanned chemotherapy ; d : discouragement of planned chemotherapy ; e : alteration of treatment sequence and/or chemotherapy regimen ; f : other . , we compared differences in the proportions between the categories of determination for cases introduced to medical oncologists and those that were not , using the chi - square test . the difference in the proportions was still significant between the groups even after excluding category a ( p=0.01 ) , for which chemotherapy was less frequent . a post - hoc analysis showed that the proportions significantly differed in categories c to f ( all adjusted p values < 0.003 ) . this study reported the current status of cb in our hospital , and investigated the influence of cbs on the treatment decisions regarding chemotherapy specifically . the results of our study showed that cbs have an influence on the treatment decisions regarding chemotherapy . we also demonstrated that cbs have an effect on the chemotherapy decisions regardless of the cancer type , since we were able to compare the cbs of the same quality across different cancers . the different pattern seen for hematology and pediatric boards was due to the lack of cases that required discussion about chemotherapy in these two groups , because there is wide consensus on the standard treatments and protocols for these types of cancer . for most cases that presented at our cbs , only issues deemed critical by the presenter were discussed . thus , cases were sometimes classified as category a ( tables 3 , 44 ) , even when chemotherapy was planned . as a result , the treatment plan might have been altered for some cases if they had been discussed at the cb . in an overview reported by croke et al . , the treatment plans were altered by cbs for about 10% of all gynecological cancer cases , and for about 20% of all gastrointestinal cancer cases ( 3 ) . in addition , van hagen et al . reported that about 30% of the cases presented at cbs resulted in an alteration of treatment ( 4 ) . given that these studies do not specify the details of such alterations , our results showing the alteration of the chemotherapy plan in 12.3% of all cases , 22.7% of gynecological , and 26.5% of gastrointestinal cancer cases thus appear to be consistent with previous studies . the gastrointestinal board showed the highest rate , which could be explained by the potential for several treatment alternatives , including surgery , radiotherapy , and chemotherapy , especially in esophageal cancers . the small rates observed for the hematology and pediatric boards arise because of the wide consensus on the standard treatments and protocols for these types of cancer , as already described above . several reports have shown that treatments recommended at cb are not implemented when palliative treatments seem ideal because of complications , or when patients do not wish to receive the treatments recommended by cb ( 3,17,18 ) . these cases belong to categories d , e , or f ( tables 2 , 33 ) , thus suggesting that these problems have been adequately discussed at our cbs . our group previously showed that cbs have a great influence on radiotherapy treatment decisions , which we have now been corroborated for chemotherapy ( 2,16 ) . nevertheless , one limitation associated with this study is that we have not yet evaluated the effect of cb on prognosis . kesson et al . reported an association between an improvement in survival for cases and having been discussed at cb ( 6 ) . therefore , we are planning to compare the survival rates between cases presented at cb and those that are not . moreover , as our group previously reported ( 2 ) , it is difficult to discuss all cases at our institution as more than a thousand cases are newly diagnosed annually ; thus , only a portion of the cases at our institution are presented at cbs . this could be one reason why only 13 cases were presented at the breast board . cases that are suited to standard therapy are rarely presented , and the treatment plans might have been altered for such cases as well , if they had been discussed at cb . the number of cases at gastrointestinal boards also seemed to be small compared to other boards . this could be explained by the fact that there is a gastrointestinal clinical conference in addition to the cb , in which clinical oncologists , but not radiation oncologists or palliative care specialists , also attend . since the gastrointestinal board is held only once a week and time is limited , cases that are unlikely to undergo radiotherapy or need specialized palliative care are discussed at this conference . in addition , we could not include any other factors that might have affected the determination of the treatment plan ; for example , age , tumor stage , and treatment received . looking at the details of the cases that were referred to the medical oncologist , cases that belonged to categories c , e , and f tended to be introduced more often ( tables 3 , 44 ) . this indicates that such cases are likely to be introduced to the medical oncologist when unplanned chemotherapy is recommended at the cbs ; this is a meaningful finding in japan since medical oncology is an emerging specialty and these cases have long been treated in their respective organ - oriented departments . these cases can also be considered ones for which management is difficult , or there is reluctance to administer chemotherapy on the part of the doctor in charge , based on the patients ' condition . cbs prompt these cases to be introduced to the medical oncologist , who fulfills the important role of giving advice with respect to treatment decisions . in conclusion , this study showed that cbs have a great influence on decisions regarding chemotherapy , and prompt necessary referrals of cases to the medical oncologist . , we will evaluate the effect of cbs on the prognosis in the near future , using the institutional cancer registry .
objective the influence of cancer boards with respect to the treatment decisions regarding chemotherapy remains to be elucidated . in the present study , we investigated the cases that presented at our institutional cancer boards , to assess the effect of cancer boards on the treatment decisions regarding chemotherapy . 
 methods data from the cancer boards at yamagata university hospital , yamagata , japan , were collected . along with data from the clinical records , 
 the details of the discussions and the chosen plan of treatment of the cancer boards were analyzed . 
 results from february 2010 to february 2014 , 1,541 cases were discussed at our cancer boards . of these , 
 811 cases ( 52.6% ) involved discussions about chemotherapy . of those 811 cases 
 , recommendations were made to alter the treatment plans for 189 cases ( 23.3% ) . 
 the reasons for discouraging chemotherapy varied ; however , 29/45 ( 64.4% ) cases involved discouragement for the following reasons : old age , a comorbid condition , the physical ( performance ) status , or insufficient evidence to administer chemotherapy . 
 eighty - six patients were referred to the medical oncology department through the cancer boards . 
 conclusion our results showed that cancer boards have a great influence on the treatment decisions regarding chemotherapy and the prompt referral of cases to medical oncologists as necessary . in terms of future research 
 , we will evaluate the effect of cancer boards on the prognosis and outcomes of cases using the institutional cancer registry .