4. 生存時間分析の報告事例 1
Title:
Impact of smoking and smoking cessation on oncologic outcomes in
primary non-muscle-invasive bladder cancer.
Authors:
Rink et al.
Journal:
European Urology, 2013
63, 724-732.
2
5. 背 景
膀胱がんの1つに、 non-muscle-invasive bladder cancer( 筋層
非浸潤性膀胱がん : NMIBC) がある。
その再発率は 50 – 70% で、 10 – 15% が5年以内に
muscle-invasive disease( 筋層浸潤性がん ) に進展する。
喫煙は、膀胱がんの発症のリスクファクターとして
確立されている。
Aromatic amines (芳香族アミン) were recognized first. At-risk groups include
workers in the following Industries: printing, iron and aluminum processing …
Another prominent risk factor is cigarette smoking, which triples the risk of developing
bladder cancer and leads to higher mortality rates (Zeeger et al.: Cancer, 89, 630-639).
Badjuk et al.: European Urology, 59, 997-1008, 2011
3
11. 統計解析
Based on their smoking quantity and duration, we divided ever smokers into four categories of lifetime cumulative
smoking exposure: light short term( 19 CPD and 19.9 yr), light long term ( 19 CPD and 20 yr), heavy≦ ≦ ≦ ≧
short term ( 20 CPD and 19.9 yr), and heavy long term ( 20 CPD and 20 yr)≧ ≦ ≧ ≧
(方法論的な問題への対処)
Follow-up time was calculated from the date of TURB. Three end points were investigated in this study: disease
recurrence, progression, and overall survival(OS) <イベントの定義> . OS probabilities were estimated
using the Kaplan-Meier method, in which patients still alive were censored at the date of their last follow-up. <打
ち切りの情報>
The log-rank test determined differences in survival function among groups. <モデルの比較> To assess
the impact of smoking on disease recurrence and progression, competing risk analyses were performed, because
smoking is an established risk factor for common health problems that increase the risk of death. <変数選択の
理由?>
The cumulative incidence was estimated, where patients who died without experiencing the event of interest were
treated as a competing event. <競合イベント>
Gray‘s test was used to determine differences in cumulative incidence function among groups. <モデル比較>
9
12. 統計解析
Multivariate Cox regression and competing risks regression models were adjusted a priori for the effects
of age, gender, pathologic T-stage and grade, number of tumors, tumor size, and intravesical therapy.
<調整変数の説明> Disease recurrence models were additionally adjusted for the effect of
perioperative chemotherapy <調整変数の説明> , as it was found to be associated with
smoking status and disease recurrence in univariable analysis.
In exploratory analyses, we examined the impact of smoking among patients receiving intravesical
adjuvant BCG therapy. Because variable distributions and outcomes differed by centre, additional
adjustment was made for study centre in all models. <調整変数の説明> Potential interactions
were tested using the likelihood ratio test.
10
24. 生存時間分析の報告事例2
Title:
Soy food intake and breast cancer survival.
Authors:
Shu et al.
Journal:
The Journal of the American Medical Association,
302, 2437-2443.
22
28. 方 法 ①
研究協力者
the Shanghai Breast Cancer Survival Study ( 20 ~ 75 歳までの
女性を対象)に参加している女性で、 2002 年 3 月~
2006 年 4 月の間に原発性乳がんと診断された者。
上海に永住。患者は the Population-based Shanghai Cancer
Registry から身元を割り出され、診断の6か月後にこの研
究に参加。
<研究集団の定義:母集団の特性、選択基準>
…診断 ICD-9
…併存疾患 Charlson comorbidity index
…がんの診断 medical record review
central review of pathological slide
研究協力者 9 名が外科治療を受けていないために除外
<除外基準>
26
32. 統計解析
The major end points for the study were any death (total mortality analysis) and cancer
recurrence/metastasis or death related to breast cancer (recurrence analysis).
<イベントの定義、発生時点>
Survival status was censored at the date of last in-person contact or May 31, 2008 (5
months before the most recent linkage to the Vital Statistics Registry) <打ち切りの情
報>
For 15 patients who died of breast cancer but had missing information about disease recurrence,
we used the disease stage(TNM)- specific median interval between disease recurrence and death
to impute the date of disease recurrence. <欠損データの処理?>
We excluded 20 patients who had a disease-free survival time of 0 from the recurrence analysis.
30
33. Cox proportional hazard models were used to evaluate the associations of soy intake with mortality and
recurrence using age as the time scale. Entry time was defined as age at diagnosis and exit time was
defined as age at event or censoring. <追跡期間の定義>
Soy protein and soy isoflavone intakes were categorized by quartile distribution and were treated as a
time-dependent variables in multivariate analysis using a counting process approach to capture the
changes in soy intake over the course of the follow-up period. <時間依存共変量?
>
We applied the restricted cubic spline function in Cox regression analyses to evaluate the association
pattern between soy food intake and mortality/recurrence. <使用する関数の説明>
In these analyses, soy protein/isoflavone intake was treated as a continuous variables; knots were placed
at the 5th, 10th, 50th, 90th, and 95th percentiles of intake; and the 10th percentile of intake was
used as the reference. Menopausal status at study enrollment was defined as cessation of menstruation for
at least 12 months.
Multiplicative interaction was evaluated using the log likelihood ratio test, which compared the model
including both main effects and interaction terms.