Page 391 - 2014 Printable Abstract Book
P. 391
Span Study data of atomic-bomb survivors show that this approach can produce smooth and flexible dose-
response estimations while reasonably handling the risk uncertainty with confidence intervals estimated
by the method of Markov Chain Monte Carlo. With few assumptions and modeling options to be made by
analyst, the method would be particularly useful in assessing the risk associated with radiation exposure
at low doses.
(S505) Lung and other respiratory cancers, smoking, and radiation risks in the LSS. Elizabeth Cahoon,
National Cancer Institute, Bethesda, MD
Lung cancer has the second highest incidence rate among solid cancers in Japan and accounts for
11% of all solid cancers observed in the Life Span Study (LSS), while other respiratory cancers (e.g.,
trachea, mediastinum) account for 0.5% of all solid cancers observed in LSS. During 1958-2009, 2,628 first
primary lung cancers, 191 laryngeal cancers, and 130 other respiratory cancers were diagnosed among
the 111,917 LSS members eligible for this study. The current data contain 11 additional years of follow-
up since the last LSS cancer incidence report. These analyses use improved smoking summary information,
updated radiation doses, and updated migration coefficients to account for migration of cohort members
into and out of the cancer registries’ catchment areas. We investigated the radiation effects on the
incidence of lung and other respiratory cancers adjusted for smoking. For lung cancer, this investigation
looks more closely at the nature of the complex departures from a simple multiplicative model.
Preliminary analyses suggest that the super multiplicative radiation/smoking interaction among light
smokers is weaker than previously reported due to the utilization of the revised smoking data.
SNC. LATE EFFECTS OF RADIOTHERAPY: NEW DOSIMETRIC APPROACHES IN EPIDEMIOLOGIC STUDIES
With cancer survivorship rates now exceeding over 50% in the developed world, better
understanding of the late effects of therapy has become even more critical. Based largely on retrospective
studies of cancer survivors and others exposed to ionizing radiation (e.g. the Atomic Bomb Survivors), the
knowledge that radiotherapy is associated with subsequent increased risk of malignant and non-
malignant conditions is now well established. However, due to the retrospective nature of most of these
studies radiation doses to critical structures must be estimated, leading to significant uncertainty in the
exact excess relative risk per dose of ionizing irradiation. Additionally, the evolution of new techniques for
delivering ionizing irradiation, such as proton therapy, intensity-modulated radiation therapy (IMRT) or
even simply the use of more customized blocking of normal tissues, proceeds much more quickly than the
accumulation of knowledge of the late effects of radiotherapy. This session will focus on the latest efforts
in radiation oncology and radiation dosimetry in particular to better quantify the exact dose-risk
relationship for a variety of conditions. The session will include presentations on 1) International
collaborative efforts to investigate the late effects of radiotherapy; 2) Techniques to prospectively
minimize and measure radiation doses received by patients; 3) Clinical aspects of radiotherapy for
prostate cancer including IMRT and protons; and 4) Recent results of radiation dose-response analyses
related to second gastrointestinal cancers.
response estimations while reasonably handling the risk uncertainty with confidence intervals estimated
by the method of Markov Chain Monte Carlo. With few assumptions and modeling options to be made by
analyst, the method would be particularly useful in assessing the risk associated with radiation exposure
at low doses.
(S505) Lung and other respiratory cancers, smoking, and radiation risks in the LSS. Elizabeth Cahoon,
National Cancer Institute, Bethesda, MD
Lung cancer has the second highest incidence rate among solid cancers in Japan and accounts for
11% of all solid cancers observed in the Life Span Study (LSS), while other respiratory cancers (e.g.,
trachea, mediastinum) account for 0.5% of all solid cancers observed in LSS. During 1958-2009, 2,628 first
primary lung cancers, 191 laryngeal cancers, and 130 other respiratory cancers were diagnosed among
the 111,917 LSS members eligible for this study. The current data contain 11 additional years of follow-
up since the last LSS cancer incidence report. These analyses use improved smoking summary information,
updated radiation doses, and updated migration coefficients to account for migration of cohort members
into and out of the cancer registries’ catchment areas. We investigated the radiation effects on the
incidence of lung and other respiratory cancers adjusted for smoking. For lung cancer, this investigation
looks more closely at the nature of the complex departures from a simple multiplicative model.
Preliminary analyses suggest that the super multiplicative radiation/smoking interaction among light
smokers is weaker than previously reported due to the utilization of the revised smoking data.
SNC. LATE EFFECTS OF RADIOTHERAPY: NEW DOSIMETRIC APPROACHES IN EPIDEMIOLOGIC STUDIES
With cancer survivorship rates now exceeding over 50% in the developed world, better
understanding of the late effects of therapy has become even more critical. Based largely on retrospective
studies of cancer survivors and others exposed to ionizing radiation (e.g. the Atomic Bomb Survivors), the
knowledge that radiotherapy is associated with subsequent increased risk of malignant and non-
malignant conditions is now well established. However, due to the retrospective nature of most of these
studies radiation doses to critical structures must be estimated, leading to significant uncertainty in the
exact excess relative risk per dose of ionizing irradiation. Additionally, the evolution of new techniques for
delivering ionizing irradiation, such as proton therapy, intensity-modulated radiation therapy (IMRT) or
even simply the use of more customized blocking of normal tissues, proceeds much more quickly than the
accumulation of knowledge of the late effects of radiotherapy. This session will focus on the latest efforts
in radiation oncology and radiation dosimetry in particular to better quantify the exact dose-risk
relationship for a variety of conditions. The session will include presentations on 1) International
collaborative efforts to investigate the late effects of radiotherapy; 2) Techniques to prospectively
minimize and measure radiation doses received by patients; 3) Clinical aspects of radiotherapy for
prostate cancer including IMRT and protons; and 4) Recent results of radiation dose-response analyses
related to second gastrointestinal cancers.
