Archive for May, 2011

Cancer Rates and New Technologies for Treating Cancer

Saturday, May 21st, 2011

Even as cancer rates decline, changing demographics and treatments are expected to dramatically increase costs in the US by 2020. A public discussion will aid the public in determining priorities—absent this discussion, very expensive treatments will be used despite their poor record, just because that’s what doctors do when nothing else has worked for the patient in front of them.

Cancer rates

US cancer rates are changing, for a variety of reasons. From the March 25, 2011 Science, pp 1540-1 (subscription needed):

Lung and bronchus Lung cancer incidence began declining among men in the early 1980s and the death rate decline began in the early 1990s. Deaths for women continue to increase. Mortality rate overall decreasing. The death rate among African-American men is far higher than for white men. The trend lags changes in smoking habits. 2010 estimated deaths: 157,300

Colon and rectum Incidence per 100,000 peaked in mid-80s, while death rate has been declining since at least 1975. Improved diet and colonoscopies are helping; mortality may drop by half by 2020. 2010 estimated deaths: 51,370

Breast (female): Rate dramatically increased in the 1980s due to efforts to detect and treat invasive breast cancer, peaking in 1999 for all races. Death rates have been decreasing steadily since 1989-90. The survival rate is far higher for whites than African-Americans. 2010 estimated deaths: 39,840

Pancreas Incidence and mortality remain constant because detection is difficult. The average patient diagnosed with advanced disease lives only 6 months. 2010 estimated deaths: 36,800

Prostrate The incidence spiked in the early 1990s with the prostrate-specific antigen (PSA) screening test, although most tumors detected by this test are non-lethal. Death rate began declining about the same time. 2010 estimated deaths: 32,050

Leukemia Incidence has remained about constant, but death rates are slowly declining due to treatments combining chemotherapy drugs. Survival rate for childhood acute lymphoblastic leukemia is now 80%. 2010 estimated deaths: 21,840

Liver The incidence and mortality from liver and bile duct cancers have been rising steadily for decades, due to increases in hepatitis B and C and alcohol abuse. Tumors usually can’t be removed with surgery, so post-diagnosis survival is short. 2010 estimated deaths: 18,910

Brain (included because of concerns about cell phones; information comes from NCI surveillance program) Incidence increased through the late 1980s (because of increased testing?) Incidence began decreasing in the late 1980s and mortality in the early 1990s. Both incidence and mortality are much higher in whites than in African-Americans (greater testing? longer life expectancy since median age at diagnosis is 56?) 2010 estimated deaths: 13,000

Treatment Costs

Can Treatment Costs Be Tamed? (March 25, 2011 Science, subscription needed) addresses the costs of cancer treatment which are increasing much faster than the population.

Over the past 3 decades, total U.S. spending on cancer care has more than quadrupled, reaching $125 billion last year, or 5% of the nation’s medical bill, according to a recent estimate. By 2020, it could grow by as much as 66%, to $207 billion. Multiple forces are driving the spiral: a growing and aging population, more people living longer with cancer, and new “personalized,” or “targeted,” therapies that can come with sticker-shock prices of $50,000 or more per patient.

Outpatient treatments are helping costs per patient decline, but these savings are swamped by the increasing number of older people, more likely to get cancer. Medicare predicts that its rolls will almost double from by 2020, from 40 million to 70 million. If all other costs stay the same, demographic changes will increase national cancer costs by 27%.

Increasing survival rates also pushes up cancer rates: the number receiving “continuing care” for breast and prostrate cancer are expected to increase 41% by 2020, adding $18 billion.

Targeted therapies may be important for society to address. Personalized therapies can be expensive, but some only extend life for a few weeks or months. One treatment for lung cancer extends life a year at a cost of more than $1.2 million. Drug costs are currently less than 15% of treatment costs, but new, costly drugs may increase their share.

Some argue that drugs that cost more/”quality-adjusted life year” than dialysis ($129,090, which would make the US still more generous than the United Kingdom, Canada, and Australia) should not be funded by Medicare and insurance, and shouldn’t be funded off-label (for cancers other than originally approved). Others argue that preventing off-label use would

hobble the proven practice of freeing doctors to find promising new uses for existing drugs. And it would stand “in stark contrast with clinical practice.” Studies, for instance, suggest that up to 75% of anticancer drugs are already used off-label. And price controls would, they argue, ultimately cause investors to reduce funding for research into new drugs because they couldn’t be sure of recouping their costs.

Both sides agree on the need for better, more organized studies.

One idea gaining favor is the idea that insurance companies would provide “coverage with evidence development”, provide coverage in order to get the data to compare effectiveness, with the aim of discontinuing coverage if drugs don’t work. “Risk-sharing arrangements” between insurers and manufacturers could link drug prices to performance.

Other topics (subscription needed):
Celebrating an Anniversary
Video: Sequencing Cancer Genomes–Targeted Cancer Therapies
Cancer Research and the $90 Billion Metaphor with Infographic (cancer information on rates)
40 Years of the War on Cancer
Combining Target Drugs to Stop Resistant Tumors
Can Treatment Costs Be Tamed?
A Push to Fight Cancer in the Developing World

Making Her Life an Open Book to Promote Expanded Care
Brothers in Arms Against Cancer (siblings of p53, the tumor-blocking protein)
Exploring the Genomes of Cancer Cells: Progress and Promise
A Perspective on Cancer Cell Metastasis
Cancer Immunoediting: Integrating Immunity’s Roles in Cancer Suppression and Promotion

Did Wedges Help Clarify the Path Forward?

Thursday, May 19th, 2011

In 2004, Robert Socolow and Stephen Pacala published an article in Science, (subscription needed) introducing the wedge: over 50 years, the savings from currently available technology could be ramped up to save 1 billion metric tons of greenhouse gases in the last year, saving in total 25 billion metric tonnes of carbon-equivalent (or 92 metric tonnes of carbon dioxide equivalent). Using optimistic assumptions about the rate of GHG growth, they calculated that 7 wedges could stabilize GHG by 2055. Of course, more sources of GHG reduction were needed to reduce GHG emissions.

Pictures help.
Socolow Wedge
Socolow Wedge

The authors emphasize paying attention to the big numbers first, the technologies that could lead to 1 billion metric tonnes of reduction in year 50.

The disadvantages in the wedge concept were in how their ideas were received. One was the appeal to so many of solving climate change with only 7 wedges (with perhaps some more to bring reductions down), the appeal of solving climate change with existing technologies, the appeal of getting to choose which solutions we want over the expert community’s more prosaic hopes that there would be enough solutions.

As of the September 10, 2010 Science, Farewell to Fossil Fuels? (subscription required), the estimate is now 25. Socolow and Pacala never said 7 wedges were enough, but the small number did make finding solutions look easier.

Socolow and Pacala encouraged this with the Stabilization Game, giving all of us a chance to vote for what we want, and vote against what we don’t want. Eventually, I rejected the wedge concept as a teaching tool because it was being abused by so many for all those reasons.

Update: It was not an interview. Socolow has posted comments, including more optimistic assumptions than I see elsewhere on the number of wedges needed.

Robert Socolow has reached the same conclusion. In a National Geographic interviewsummary of a Socolow talk, he now says the wedge concept was a mistake:

“With some help from wedges, the world decided that dealing with global warming wasn’t impossible, so it must be easy,” Socolow says. “There was a whole lot of simplification, that this is no big deal.” …[I]nstead of providing motivation, the wedges theory let people relax in the face of enormous challenges, he now says.

“The job went from impossible to easy” in part because of the wedges theory. “I was part of that.”

And from there, he says, a disturbing portion of the population moved to doubt that the problem is even real…

“The intensity of belief that renewables and conservation would do the job approached religious,” Socolow said. But the minimum goals “are not enough,” he said, and “the fossil fuel industry will not be pushed over.”

Who was most likely to abuse the web concept?

Henry Lee, who directs the environment program at the Harvard Kennedy School’s Belfer Center for Science and International Affairs, said many people were optimistic that, by now, the world would be making considerable progress on climate.

“I think we were victimized more by the advocacy community than by science,” Lee said. Using Socolow’s wedges theory and similar arguments, advocates suggested “you could get all of this and pay nothing. I think people feel angry now, that it’s going to cost them.”

Lee agreed Socolow’s ideas were misused, or at least misread. “If you look at the wedges they weren’t a little. There was nothing in the Socolow plan that says this is a slam-dunk and easy to do.”

“The wedge theory still is valuable,” Lee added. “The price tag may be higher, but I think he made an important contribution. If you’re going to do something about climate change, there is not one silver bullet. That’s the point he made at the time, and it’s still valid.”

Hopefully, we can still use some of what they taught (focus on the large, the solutions are silver buckshot). Hopefully we can find ways to help the advocacy community understand that we don’t have so many solutions that we can reject any.

IPCC: Special Report Renewable Energy Sources

Wednesday, May 11th, 2011

Intergovernmental Panel on Climate Change’s new report, Special Report Renewable Energy Sources (SRREN), is due out soon. The summary for policymakers (pdf) is available now.

The questions this report addresses are important: how much electricity and other energy can be supplied by renewables? At what cost? This report (more so the full report and technical summary) will help us make sense of conflicting claims today. All policy experts agree that renewables are needed, along with other low-carbon forms of energy, but what is their potential in the coming decades?

How much energy comes from renewables today?
Currently, world primary energy is 492 exajoules (the joule is the metric unit of energy. 1 exajoule = 10^18 joules = 1 billion billion joules = 278 terawatt hours (trillion watt hours or billion kWh).

Renewables supply 12.9% of this energy, of which 60% is traditional biomass, eg, wood, used for cooking and heating. 10.2% of all energy, 80% of all renewables, is biomass of some kind. Of the remaining 2.7%, 2.3% is hydro, 0.4% is other.

The graphs are a little confusing; energy sources are placed on different graphs because there is so much more of some than others. Recent gains in solar are impressive—photovoltaics, solar panels are up by almost a factor of 10 in 4 years, but the absolutely increase in exajoules pales compared to increases in other forms of renewables, from hydro to municipal solid waste. Also, information is often given in capacity, or GW—capacity tells us how much power is produced, at a maximum—rather than in GWh, total energy produced. [For example, German photovoltaics, with their 9.5% capacity factor, produce half as much electricity per GW as do PV in California, where the capacity factor is twice as large. Wind generally does better, but German wind has a capacity factor of less than 20%, while American wind is more than 30%. (To compare, American nuclear power capacity factor is >90%). So 1 GW of German solar produces half as much electricity as 1 GW of CA solar or German wind, and less than 1/3 as much as US wind.]

Most renewables except hydro and geothermal are more expensive than non-renewables. The costs of many are expected to decline.

How much energy can come from renewables by 2030? 2050?
The full report examines 164 scenarios. The use of renewables increases under all scenarios, no surprise. In the most ambitious scenario, renewables supply up to 43% of energy in 2030 and 77% in 2050. Half of scenarios show a contribution of >17% in 2030 and >27% in 2050.

Bioenergy appears to supply half or more of renewables in both Annex I and non-Annex I countries. Here are the median (half are higher, half are lower) estimates for 5 types of renewables (Annex 1/non-Annex 1), read from the graphs:
• bioenergy: 30 EJ/70 EJ
• hydro: 10 EJ/15 EJ
• wind: 10 EJ/15 EJ
• solar: 8 EJ/12 EJ
• geothermal: small
Marine energy is thought to be relatively unimportant in 2050.

The highest estimates assume a combined 430 EJ/year, considerably more than the median. Bioenergy, solar, and wind are much higher than the median in some scenarios.

The cost, depending on how ambitious the goal, would be $1.4 – 5.1 trillion between now and 2020, and $1.5 – 7.2 trillion between 2021 and 2030. For some renewables, there would be savings later because fuel costs are less. Costs of the renewables themselves are uncertain, and there are additional costs:

The costs associated with RE integration, whether for electricity, heating, cooling, gaseous or liquid fuels, are contextual, site-specific and generally difficult to determine. They may include additional costs for network infrastructure investment, system operation and losses, and other adjustments to the existing energy supply systems as needed. The available literature on integration costs is sparse and estimates are often lacking or vary widely.

So costs depend. Also, maintaining system reliability will become more difficult, but having a portfolio of renewables reduces risks and costs of grid integration.

What might interfere with some of the more ambitious plans?
First, hydro and bioenergy availability is less certain in the future:

Climate change will have impacts on the size and geographic distribution of the technical potential for RE [renewable energy] sources, but research into the magnitude of these possible effects is nascent…Because RE sources are, in many cases, dependent on the climate, global climate change will affect the RE resource base, though the precise nature and magnitude of these impacts is uncertain. The future technical potential for bioenergy could be influenced by climate change through impacts on biomass production such as altered soil conditions, precipitation, crop productivity and other factors. The overall impact of a global mean temperature change of below 2°C on the technical potential of bioenergy is expected to be relatively small on a global basis. However, considerable regional differences could be expected and uncertainties are larger and more difficult to assess compared to other RE options due to the large number of feedback mechanisms involved. For solar energy, though climate change is expected to influence the distribution and variability of cloud cover, the impact of these changes on overall technical potential is expected to be small. For hydropower the overall impacts on the global potential is expected to be slightly positive. However, results also indicate the possibility of substantial variations across regions and even within countries. Research to date suggests that climate change is not expected to greatly impact the global technical potential for wind energy development but changes in the regional distribution of the wind energy resource may be expected. Climate change is not anticipated to have significant impacts on the size or geographic distribution of geothermal or ocean energy resources.

[The following were not mentioned in the SPM, though they may be included in the main report:
• A study just published in Science says that the climate already may be affecting worldwide wheat and maize (corn) production.
• There is a likely link between hydro and the Sichuan earthquake which killed 70,000. Worries about earthquakes could reduce the addition of hydro.
MIT analysis suggests wind turbines could cause temperatures to rise.]

The report emphasizes that the potential for renewable energy is large. However,

Factors such as sustainability concerns, public acceptance, system integration and infrastructure constraints, or economic factors may …limit deployment of renewable energy technologies.

There are some steps between here and there:

A variety of technology-specific challenges (in addition to cost) may need to be addressed to enable RE to significantly upscale its contribution to reducing GHG emissions. For the increased and sustainable use of bioenergy, proper design, implementation and monitoring of sustainability frameworks can minimize negative impacts and maximize benefits with regard to social, economic and environmental issues. For solar energy, regulatory and institutional barriers can impede deployment, as can integration and transmission issues. For geothermal energy, an important challenge would be to prove that enhanced geothermal systems (EGS) can be deployed economically, sustainably and widely. New hydropower projects can have ecological and social impacts that are very site specific, and increased deployment may require improved sustainability assessment tools, and regional and multi-party collaborations to address energy and water needs. The deployment of ocean energy could benefit from testing centres for demonstration projects, and from dedicated policies and regulations that encourage early deployment. For wind energy, technical and institutional solutions to transmission constraints and operational integration concerns may be especially important, as might public acceptance issues relating primarily to landscape impacts.

There can be challenges integrating the renewables into the grid.

The characteristics of different RE sources can influence the scale of the integration challenge. Some RE resources are widely distributed geographically. Others, such as large scale hydropower, can be more centralized but have integration options constrained by geographic location. Some RE resources are variable with limited predictability. Some have lower physical energy densities and different technical specifications from fossil fuels. Such characteristics can constrain ease of integration and invoke additional system costs particularly when reaching higher shares of RE.

Water availability could affect hydropower, bioenergy, and thermal plants (such as solar thermal or biomass).

Modeling GHG emissions from biomass is particularly difficult because of land use change. In order to grow plants for electricity or fuel, the land is converted from another use (such as forest).

And it could be even better
Potentially, the use of biopower with carbon capture and storage may reduce atmospheric carbon. This is because plants take carbon dioxide out of the air, and release it back when burned to make electricity or fuel. CCS could be used when making electricity, so that the carbon dioxide goes into long-term storage.

By 2050, renewables may be more attractive than other low-GHG forms of energy, such as nuclear or carbon capture and storage.

Many combinations of low-carbon energy supply options and energy efficiency improvements can contribute to given low GHG concentration levels, with RE becoming the dominant low-carbon energy supply option by 2050 in the majority of scenarios.

[Note: more will be known in a decade or three on the costs of the various renewable technologies, as well as the costs of nuclear and carbon capture and storage. And more will be known about the pitfalls of all technologies.]

This report is a welcome addition to IPCC policy analysis.