Cancer is such a complex and misunderstood disease; personalized approach are need for chemotherapy , surgery and every other treatments options available  .

Cesar. SO. Surgical Oncology. md Anderson Hospital H,Tx.

Anticancer drug therapies include chemo (mostly cytotoxic), targeted therapy and immuno therapy.  Their cure rate is highly variable depending on individual patient. The predictors are still mostly unknown.  

I believe you are mistaken in your assumption that "each type of cancer is triggered by a different factor; different causes of cancers, need different types of treatment".  In fact, a very similar set of epigenetic changes must occur to "silence" genes that normally control cellular proliferation in almost all cancer types. The nature of the cancer is the most important characteristic defining its ability to be cured. Across many types of cancer, a stem cell-like profile of gene expression defines a "death from cancer phenotype", i.e., one that predicts that treatment will fail resulting in death. Single tumours are very heterogeneous, with a very small proportion of the cells within a tumour displaying stem cell-like properties.  These are known as cancer stem cells.  The stepwise progression of almost all cancers involves very defined epigenetic changes, including the inappropriate silencing of genes important in controlling cell division and apoptosis, among others.  It is these cancer stem cells which resist treatment; they are very efficient at repairing DNA damage caused by the most common cancer treatments allowing them to survive therapy, escape the primary tumour, and spread cancer throughout the body, eventually resulting in death. Thus it is the cancer stem cells that must be ablated during treatment, yet cancer stem cells are extremely resistant to the common DNA damaging therapies including radiation and chemo that are based on DNA damage.  The conclusion is that most current therapies only work well at killing the bulk of the tumour cells, explaining why early diagnosis is the best correlation with cure, but more important is the "stem cell nature" of cancer. As tumour cells with stem cell properties arise, i.e., cancer stem cells, the ability of these untargeted therapies to result in a cure dramatically diminishes. Once a cancer stem cell survives therapy it becomes that much harder to destroy during any additional intervention.

For more information on this, I would recommend two older reviews I have done in this area which are available on my profile. 

 ill surely read them,, Dr what are the top triggers for cancer currently?

I haven't seen anyone cured by chemotherapy in bad cases of cancer where we have a big metastasis, just adding problems and more pain to the patient.

Hi Fatima,

There is a long list of triggers but things like age, negative mutations, and diet would be included. Most cancers are caused/triggered by a stepwise accumulation of genetic (some of these could be inherited, such as BRAC1 mutations or be induced by radiation, mutagens, age etc.. ) and epigenetic errors (some of these could be induced by lifestyle, diet, age, radiation exposure etc....) that combine to promote cellular growth and turn off the control of cellular proliferation in damaged cells, with some exceptions, such as translocation of a gene coding for a growth-promoting protein into a position in the genome that contains a strong promoter, or where the translocation results in an abnormal fusion protein that functions to aberrantly promote cellular growth. These translocations can cause very aggressive cancers, yet to progress other changes are also required. In normal cells, DNA damage that is not repaired leads to apoptosis or senescence, and almost all cancers have to have errors at the Ink/ARF locus or the related p53 tumour suppressor pathway to progress (inappropriate gene silencing through epigenetic modifications being common).  Thus the specific "trigger" for two cases of the same cancer type may not be the same, yet both will require changes to the genes that control proliferation before the tumour becomes actual metastatic cancer with the ability to spread.  

Both radiotherapy and many common chemo drugs work in similar ways. They damage the cancers DNA hoping that the damage will lead to cell death, but this approach is very nonspecific damaging normal cells as well which increases the risk of developing other cancers in the future. This approach also depends on the ability of cancer cells to go through the process of apoptosis (programmed cell death) or senescence. The problem is that, like our normal stem cells, cancer stem cells are themselves very good at DNA repair, and a "cure" requires the death of every cancer stem cell. When the bulk of a cancerous tumour is destroyed but a few cancer stem cells remain, this is called remission.

Much of the current research is dedicated to finding ways to "sensitize" these cancer stem cells to current treatment modalities or to develop specific inhibitors of the pathways that are inappropriately activated within the cancer stem cell. You would probably find my DNA repair and gene silencing reviews helpful to further illustrate these concepts.

wow thank you for the valuable information!

Dear colleague,

Chemo therapy is traditional way of anti cancer treatment which will be shot down in up comming future times. It is very unspecific, toxic, damaging and non target therapy.

However, some cancers can be treated with this kind of treatment, mostly high chemo sensitive cancers such as acute leukemias /only some of them/, Hodgkin lymphoma and aggressive NHL, some small cell nueriendocrinic sarcomas such as Ewing or embrional rhabdomyosarcoma, but only in highly selected cases. We dont know predicitve factors for cancer sensitivity, but we have to treat people with something what we have as a medical weapon at this time point. Benefit is sudden but long time survivors are at hihg risk of secondary cancers develompent, or organ damage /heart, lungs, kidneys, nerves.../.

We can all see the dramatic changes of the landscape in future anticancer treatment /target agencies/. The crucial problem is to destroy cancer stem cells which survive treatment in most of cases when chemo is used. Even target therapy is still incapable to do that.

I don't see at this time point the resolving of mistery of cancer stem cells survival. 

Greetings from Serbia, Nis

First question is "what is cancer" , if we can answer this question , we can ask other questions (Is chemotherapy a real cure for cancer? ..etc)

please see our project

https://www.researchgate.net/project/Testing-New-Cancer-Theory-Cancer-is-clonal-system-with-the-cancer-type-genome-chaos-for-adaptive-evolution

regards

Only combinations across therapies with different mechanisms could use the word ‘cure’ to real world, sometimes, a stabilized chronic status of cancer may be a more appropriate way to describe it.  

Please, do not miss the point!

If we want to define the number or percentage of cancer patients cured from cancer by chemotherapy, you should be aware, that there are two basic setup are existing in oncology, when cure of cancer could be achieved by chemotherapy itself..

The first one is the treatment of micrometastatic disease, it is the so called adjuvant treatment, when patient is treated by chemo after surgery done with curative intent and no detactable residual tumor mass left in the body. It is a textbook material, that relapse rate depends from the stage of the tumor, and in case of specific tumors (like colorectal, or breast cancer) this relapse rate can be effectively reduced by appropriate postoperative chemo. This reduction of relapse rates are reflects the number or proportion of patients cured from cancer by the chemo itself. Other variation of this setting is the so called neoadjuvant or primary systemic treatment, when chemo delivered before the surgical procedure, and this combination efforts result lower relapse rate or extended survival. Easy to see, that improvement in clinical outcomes are also results of (curative) chemos applied. In the neoadjuvant (preoperative) treatment usually has a double effect, they are fighting against micromets, and also decrease the size of the visible primary or met planned to be resected.

The other situation when you are treating macroscopic tumor. Mostly the purpose of this treatment is palliatíve, because the cure rate is really low. Eg. in case of metastatic colorectal cancer, the cure rate is 0,6% from targeted therapy utilizing combination protocols. But there are few cases of cure. Other tumors, like stage III testicular cancer, can be treated effectively by chemo, and depending on prognostic features, cure rate can be as high as 96%.

Another very important area of the utilisation of chemo when there is a metastases which is not resectable, but it could became suitable for removal in case of shrinkidge. Eg. considerable portion of liver only colorectal cancer mets became resectable after appropriate conversion combination therapy, and for these patients, resection is the only way to achive cure.  The same can be applied, if you use chemo together with radiation (chemoradiotherapy) to shrink the tumor before surgery, it also improves survival endpoints so it has to be considered as curative approach.

Needless to say, that more tumor mass means less effective chemo. But never forget: that unpredictable individual factors can mess up everything...

Cancer is such a complex and misunderstood disease; personalized approach are need for chemotherapy , surgery and every other treatments options available  .

Cesar. SO. Surgical Oncology. md Anderson Hospital H,Tx.

Very good but very complex question! Why? It is a disease that is very complex in itself! Depends on cancer when it is diagnosed whether it has metastasized or not! If it has metastases then it is most likely only a palliative therapy! Did it give micrometastatice metastases, which can hardly be proven at first, but when metastasis occurs, it clearly confirms this suspicion! I mean while the cancer is localized at the beginning that the most effective curative therapy for malignancies is Surgery, Carcinoma Removal!

I completely agree with my colleague's opinion Ladislaus L. Torday!

Dear Fatima Rifai,

Your observations are certainly true but not without a reason. Lets refresh our memory a bit. Tumor is different from cancer. Benign tumor is different from malignant tumor which is cancer. Whatever type of cancer it is, the location in the body takes precedence. In the blood, we say blood cancer, in the prostrate, we say prostrate cancer, in the skin, liver, kidney, just mention them- you won't get less than 250 forms of it.

What is then cancer? Cancer is d uncontrollable proliferation of cells usually occasioned by mutation caused by several agents from environmental factors to biological factors including microbes.

How do u cure a cell replicating at an unsual speeed? With what medication? Is it replicating at one location in the body? In the blood or head? Critical location? When start? Chemotherapy treatment or surgery-chemotherapy? Will tampering elevate it? Are there influence of genetic variations on drugs. Who handes it? a meticulous expert or a careless expert? So many factors.

Some cases of cancer has been treated successfully while many has been unsuccessful. Many Great men and women of valour battled cancer all there lives yet cancer won. The less privileged ones are overpowered. 

Way forward: Substantial progress has been made. This deserves commendations. Keep the figures & statistics. Research is ongoing for the search suitable cancer remedies. Working on text right now as project that will capture some aspects of cancer here. Cancer will be defeated 

valuable information, thanks