Nifurtimox br On the other hand most other Asian
On the other hand, most other Asian populations (Japan, Hong Kong, Shanghai and Singapore) show downward inflections for birth cohorts born around the 1950s. Despite having similar downward in-flections with most of the other Asian populations. Japan also has up-ward inflections for its cohorts born around the 1960s, similar to the Western populations. There are also some apparent upward inflections toward the more recent cohorts for Hong Kong, Shanghai and Singapore. Nevertheless, the confidence intervals are wider toward the more recent cohorts, rendering the interpretations less definite. There
are no significant changes in the cohort eﬀects for India.
This is the first comparative population-based study that examined the age, Nifurtimox and cohort eﬀects on CRC incidence across diﬀerent countries representing the West versus the East.
First, regarding the age-standardized incidence rates across the countries, we observed that the incidence rates had stabilized in the UK and Australia, and even had declined in the US during the past 30 years. These happened to be the long-term developed Western countries, which also shared more similar socio-cultural and lifestyle background than the other non-Western countries. At the other end, Shanghai, being the most economically developed city in Mainland China, has an in-creasing CRC incidence rate during the past 20 years, which also co-incides with its more current rapid socio-economic development after the implementation of the Open Door Policy in China . It is also noteworthy that Japan has witnessed both a steady increase in the CRC incidence rates from 1970s to early 1990s, and a plateau afterwards, and its pattern of CRC incidence seems to coincide with its pattern of socio-economic development, where its economy rapidly grew in the 1960s and slowed down in the 1990s [28,29]. Similar pattern of growth and plateau of CRC incidence can also be observed in Singapore, which also experienced socio-economic development after the 1960s [29,30]. It is also interesting that Hong Kong, sharing similar socio-cultural and lifestyle background with Singapore , witnessed a rather similarly stable pattern of CRC incidence as Singapore from the 1980s onwards; however, due to the relatively shorter length of data for Hong Kong, we were unable to observe whether the CRC incidence was also rapidly increasing as in Singapore during the 1960s and 1970s. Given these observations, one can speculate that there may somehow be association between CRC incidence and general socio-economic development; however, longer period of data is needed to confirm such relationship.
Second, the age eﬀects of incidence generally increase across all populations. This is consistent with the literature that CRC is a disease of the advancing age . Particularly interesting is the slight decline of age eﬀects toward the older age groups in the West, which is not apparent in the Asian populations. This may be reflective of the in-creased proportion of adults over 50 years undergoing CRC screening with the launch of nation-wide programs during the past several dec-ades in these countries [32–35].
Third, there are no apparent second-order change in period eﬀects with the exception of Japanese and Indian. However, out of almost all the populations under study, the observed periods are relatively short; longer period of observation is warranted for further interpretations.
Finally, there are diﬀerential cohort eﬀects on CRC incidence be-tween the Western populations (UK, US and Australia) and the Asian populations (Japan, Hong Kong, Shanghai and Singapore). There is generally an increased cohort eﬀects for cohorts born after the 1950s and 1960s in the UK, the US and Australia. On the contrary, a generally declined cohort eﬀects for the 1950s generations in the Asian popula-tions is observed. In other words, there is a phenomenon of increased CRC cohort eﬀects being shifted toward the younger generations in the Western populations, while this increase is not as apparent for the 1950s generations of the Asian populations. Two possible explanations are oﬀered here.